diff --git a/goodwe_controller/DECISIONS/PRICE-02-the-verdict-skips-ended-periods.md b/goodwe_controller/DECISIONS/PRICE-02-the-verdict-skips-ended-periods.md
index e4f994e..0ee7b46 100644
--- a/goodwe_controller/DECISIONS/PRICE-02-the-verdict-skips-ended-periods.md
+++ b/goodwe_controller/DECISIONS/PRICE-02-the-verdict-skips-ended-periods.md
@@ -17,7 +17,9 @@ ended (`end <= now`, the span `price._cover_table()` gives, as
   still used at 03:20, and the Home chart keeps the day's earlier bars.
 - An hourly point that is still current stays in, so hourly feeds and the
   static day/night plan give the same verdict as before.
-- `now=None` keeps the old reach (the whole series); only tests leave it out.
+- `now` is required: keyword-only, no default, like the other three arguments. A
+  caller that could leave it out would get the elapsed periods back and the
+  defect with them. A test that wants the whole series passes an instant before it.
 - The sentences of this verdict in `arbitrage.py` (status row and action log,
   English only) say "price period" where they said "hour": the idle one now
   reads "now is not the cheapest or the dearest price period". The UI texts
@@ -30,3 +32,38 @@ the same too; only a sale's sentence quotes a smaller "above the cheapest"
 figure once the first cheap period is over. The identity pins in
 `test_modes_p3.py` and `test_price_run_fixes.py` hide just that figure and the
 word change (`opt11p3_identity.trade_digest()`).
+
+## Ties (round 2)
+
+The verdict takes `min`/`max` over the points still ahead and the first one wins
+a tie, so with equal prices it is the first period still ahead, which is the
+current one. Before, it was the first of the whole plan, often one that had
+ended. Two effects follow, and both are the card's intent, not a side effect:
+
+- Equal quarters (hour-constant data, or a feed that prints the same price in
+  several quarters) now act in every quarter of the cheap (or dear) block,
+  not in the first only. Test: `test_price02.py` part 6.
+- After the cheapest period has passed, the next cheapest still ahead is the
+  target, if its spread still clears the cost. A hourly plan did this at every
+  refresh already (it started at the current hour); a 15-minute plan did it
+  only from the next hour on, because it kept the elapsed quarters of this one.
+
+Measured with `scratch/PRICE-02/dev/tiesim.py` (refresh every 30 min from the
+floored hour, verdict at 7 min into each period, threshold 0.05, old = the
+verdict over the whole plan, new = this card):
+
+| data | days | acting periods old -> new | action changes old -> new |
+|---|---|---|---|
+| real 15-minute day, energy-charts 2026-09-09 | 1 | 4 -> 5 | 6 -> 6 |
+| real 15-minute days 2026-09-09 and -10 | 2 | 14 -> 26 | 24 -> 24 |
+| EPEX 2025-26 hourly prices as four equal quarters | 12 | 18 -> 72 | 36 -> 20 |
+| the same with random +-0.002 noise per quarter (no ties) | 12 | 18 -> 33 | 36 -> 48 |
+
+So a real 15-minute day does not switch more often (24 -> 24), and a day of
+equal quarters switches less. A synthetic day of noisy, tie-free quarters does
+(3.0 -> 4.0 changes a day): each period that passes hands the target to the
+next cheapest one ahead. Every change is still at a period edge, never within
+one. The replay in `test_arbitrage.py` (synthetic year, hourly) gives the same
+ledger on the old and the new code once its ties are broken (280 round trips,
+85 held, both): it printed one maximum twice per day, and the old fixture
+tested the first of them only because its plan began at midnight.
diff --git a/goodwe_controller/app/homeview.py b/goodwe_controller/app/homeview.py
index 392cf63..dfc6940 100644
--- a/goodwe_controller/app/homeview.py
+++ b/goodwe_controller/app/homeview.py
@@ -262,7 +262,7 @@ def _run(i, kind, start, end, day0, day1, what, why, amount, *, kwh=None,
             "eur_kwh": None if price is None else round(price, 4)}
 
 
-def trade_verdict(c, plan, now=None):
+def trade_verdict(c, plan, now):
     """The arbitrage verdict the control cycle would reach on this plan, or a
     reason there is none. The SAME call and inputs as `Controller.cycle()`:
     `plan.arbitrage()` with the peak guard's state, the cycle cost and the
@@ -284,7 +284,7 @@ def trade_verdict(c, plan, now=None):
         refused=lambda _v: (None, refusal_key(plan, guard, now)))
 
 
-def refusal_key(plan, guard, now=None):
+def refusal_key(plan, guard, now):
     """Which of `TariffPlan.arbitrage()`'s refusals fired, in its own order:
     the peak guard, no prices, under two published points, then the gap."""
     if guard:
@@ -292,9 +292,8 @@ def refusal_key(plan, guard, now=None):
     if not plan.has_prices:
         return "no_prices"
     pts = _points(plan)
-    if now is not None:
-        ahead = {id(p) for _s, end, p in _cover_table(pts) if end > now}
-        pts = [p for p in pts if id(p) in ahead]
+    ahead = {id(p) for _s, end, p in _cover_table(pts) if end > now}
+    pts = [p for p in pts if id(p) in ahead]
     if sum(1 for p in pts if not p.provisional) < 2:
         return "not_firm"
     return "not_worth"
diff --git a/goodwe_controller/app/static_tariff.py b/goodwe_controller/app/static_tariff.py
index 204c5e2..013b7ee 100644
--- a/goodwe_controller/app/static_tariff.py
+++ b/goodwe_controller/app/static_tariff.py
@@ -986,20 +986,25 @@ class TariffPlan:
         return here.eur_per_kwh < (sum(p.eur_per_kwh for p in firm) / len(firm))
 
     def arbitrage(self, *, peak_guard_active: bool, min_spread_eur_kwh,
-                  uncertainty, now: datetime | None = None) -> Arbitrage:
+                  uncertainty, now: datetime) -> Arbitrage:
         """May OPT-04 trade, and on what numbers. See the module docstring.
 
         PRICE-02. `now` (tz-aware) drops the points whose price period has
         ended (`end <= now`, the span `price._cover_table()` gives it), so the
         cheapest and dearest point are always ones that can still be traded.
         It is taken here, per call, and not when the plan is built: a plan
-        built at 03:00 is still used at 03:20. Every caller passes its own
-        `now`. An hourly point that is still current stays in. Left out
-        (None), the whole series counts, as before.
+        built at 03:00 is still used at 03:20. An hourly point that is still
+        current stays in.
 
-        ⚠️ ALL THREE ARGUMENTS ARE REQUIRED AND KEYWORD-ONLY, for one reason
+        ⚠️ ALL FOUR ARGUMENTS ARE REQUIRED AND KEYWORD-ONLY, for one reason
         each, and none of them has a default:
 
+          `now`                 PRICE-02. A caller that could leave it out
+                                would get the whole series back, elapsed
+                                periods included, and the verdict could aim
+                                at a period that is over. A test that wants
+                                the whole series passes an instant before it.
+
           `peak_guard_active`   §9.1/§10.1 put peak shaving above arbitrage,
                                 and this is how that ordering survives a
                                 strategy that has not been written yet: the
@@ -1037,6 +1042,12 @@ class TariffPlan:
                 f"{sorted(map(repr, caller_sources))} - a string widens by "
                 f"nothing while reporting that it widened.")
 
+        if not isinstance(now, datetime) or now.tzinfo is None \
+                or now.utcoffset() is None:
+            raise TypeError(f"now must be a tz-aware datetime, not {now!r}; "
+                            f"a naive instant is ambiguous for one hour "
+                            f"every October")
+
         if peak_guard_active:
             return Arbitrage.refuse(
                 "the capacity-tariff peak guard is holding, and §10.1 puts peak "
@@ -1064,12 +1075,8 @@ class TariffPlan:
         # day with no fetch at all) has no firm pair left and is refused, which
         # is the previous behaviour arrived at by a truer route.
         pts = self.read.points
-        if now is not None:
-            if now.tzinfo is None or now.utcoffset() is None:
-                raise TypeError("now must be tz-aware; a naive instant is "
-                                "ambiguous for one hour every October")
-            ahead = {id(p) for _s, end, p in _cover_table(pts) if end > now}
-            pts = tuple(p for p in pts if id(p) in ahead)
+        ahead = {id(p) for _s, end, p in _cover_table(pts) if end > now}
+        pts = tuple(p for p in pts if id(p) in ahead)
         firm = tuple(p for p in pts if not p.provisional)
         if len(firm) < 2:
             # ⚠️ POINTS, AND THE HOUR FIGURE BESIDE IT RATHER THAN INSTEAD OF
diff --git a/goodwe_controller/test_arbitrage.py b/goodwe_controller/test_arbitrage.py
index c29cb6d..cfe3f70 100644
--- a/goodwe_controller/test_arbitrage.py
+++ b/goodwe_controller/test_arbitrage.py
@@ -93,11 +93,9 @@ from app.control import Tuning, compute
 from app.p1 import QUARTER_S, QuarterAverager, make_sample, split_signed
 from app.tariff import PeakTracker
 from app.arbitrage import (
-    CHARGE, DISCHARGE, ArbitrageDecision, claim, enabled, soc_bounds,
+    CHARGE, DISCHARGE, ArbitrageDecision, claim, decide, enabled, soc_bounds,
     threshold_eur_kwh,
 )
-from app.arbitrage import decide as _decide_now
-from app.price import _cover_table as _cover
 # SAFETY-47 section 3d. The shipped shadow-mode row, not a transcription of it.
 from app import shadow as _shadow
 from app.price import (
@@ -111,30 +109,14 @@ from app.validate import validate_startup_config
 
 UTC = timezone.utc
 HERE = os.path.dirname(os.path.abspath(__file__))
+
+# PRICE-02: `TariffPlan.arbitrage(now=...)` is required. This instant is before every
+# point these fixtures build, so no period has ended and the whole series counts.
+from datetime import datetime as _DT, timezone as _TZ  # noqa: E402
+LONG_AGO = _DT(2000, 1, 1, tzinfo=_TZ.utc)
 fails = []
 
 
-def decide(plan, now, **kw):
-    """`arbitrage.decide()` on the plan as a running site holds it at `now`.
-
-    PRICE-02: the verdict drops price periods that have ended. These fixtures
-    are whole-day plans probed at every hour, so the periods before `now` are
-    moved one day on (the next day's prices are the same): the plan then
-    starts at `now`, as a refreshed plan does, and every check keeps asking
-    what it asked before. Nothing before `now` is left to drop. The new
-    behaviour itself is graded in test_price02.py."""
-    if plan is None or plan.read.kind != "series":
-        return _decide_now(plan, now, **kw)
-    r = plan.read
-    pts = [PricePoint(start=brussels(p.start + timedelta(hours=24)),
-                      eur_per_kwh=p.eur_per_kwh, provisional=p.provisional)
-           if end <= now else p for _s, end, p in _cover(r.points)]
-    pts.sort(key=lambda p: p.start)
-    rolled = TariffPlan(PriceRead.series(pts, r.product, r.provider,
-                                         r.fetched_at), plan.profile, plan.origin)
-    return _decide_now(rolled, now, **kw)
-
-
 def check(name, cond):
     print(f"  {'ok  ' if cond else 'FAIL'} {name}")
     if not cond:
@@ -217,13 +199,22 @@ NO_WEATHER = frozenset({Uncertainty.NO_WEATHER})
 
 
 def plan_of(prices, *, product=PriceProduct.DAY_AHEAD, start=D0,
-            provisional=False, provider="generic_dayahead"):
+            provisional=False, provider="generic_dayahead", days=2):
     """A TariffPlan over consecutive hourly prices starting at `start`.
 
     `provisional` may be a single bool or a per-hour sequence.
+
+    PRICE-02: the verdict skips price periods that have ended, so a plan
+    probed at 18:30 no longer sees the cheap hour at 03:00 of the same day. A
+    running site holds 24-48 h, so `days=2` repeats the day (tomorrow's
+    prices are today's): probes in day one keep their extremes, and the
+    first cheapest/dearest hour still ahead is today's. Pass `days=1` for a
+    plan that must be exactly the given hours.
     """
+    prices = list(prices) * days
     flags = ([bool(provisional)] * len(prices)
-             if isinstance(provisional, bool) else list(provisional))
+             if isinstance(provisional, bool)
+             else list(provisional) * days)
     pts = [PricePoint(start=brussels(start + timedelta(hours=i)),
                       eur_per_kwh=round(float(p), 6), provisional=f)
            for i, (p, f) in enumerate(zip(prices, flags))]
@@ -367,7 +358,7 @@ check(f"a realistic Belgian day/night profile has a spread of "
       f"{_st_spread!r} EUR/kWh - the number the product decision is about",
       near(_st_spread, 0.08))
 _shipped = PRICE_OPTION_DEFAULTS["cycle_cost_threshold_eur"]
-_st_verdict = derived(lambda: _st_plan.arbitrage(
+_st_verdict = derived(lambda: _st_plan.arbitrage(now=LONG_AGO,
     peak_guard_active=False, min_spread_eur_kwh=_shipped,
     uncertainty=NO_WEATHER))
 check(f"...and at the SHIPPED threshold of {_shipped} EUR/kWh that site does "
@@ -384,7 +375,7 @@ check(f"...and it is the SPREAD rung that refuses it, not a flat-tariff or a "
 check("...while the SAME site trades once the threshold is set below its "
       "spread, so the refusal above is about the number and not about static "
       "tariffs being unsupported",
-      derived(lambda: _st_plan.arbitrage(
+      derived(lambda: _st_plan.arbitrage(now=LONG_AGO,
           peak_guard_active=False,
           min_spread_eur_kwh=_st_spread / widen_factor(NO_WEATHER) - 1e-4,
           uncertainty=NO_WEATHER).kind) == "allowed")
@@ -707,12 +698,12 @@ check("...and the interlock is REQUIRED rather than defaulted: "
       "caller cannot reach a spread without having answered it",
       all(p.default is inspect.Parameter.empty
           for n, p in inspect.signature(TariffPlan.arbitrage).parameters.items()
-          if n not in ("self", "now")))   # PRICE-02: now=None keeps the old reach
+          if n != "self"))
 check("...nor does arbitrage.decide(): every argument of it is keyword-only "
       "with no default, for the same reason",
       all(p.default is inspect.Parameter.empty
           and (p.kind is inspect.Parameter.KEYWORD_ONLY or n in ("plan", "now"))
-          for n, p in inspect.signature(_decide_now).parameters.items()))
+          for n, p in inspect.signature(decide).parameters.items()))
 
 # MECHANISM 2: the arbiter. Even with the interlock bypassed, the peak claim
 # binds the arbitrage claim - because P_PEAK > P_ARBITRAGE and clause 2 applies
@@ -1667,7 +1658,7 @@ check("a FULLY carried series trades nothing at all, whatever its spread - "
 # standing if a future caller ever hands `_act` a plan the verdict did not come
 # from.
 _probe = _arb._point_at(PLAN, hour(CHEAP_H))
-_verdict = PLAN.arbitrage(peak_guard_active=False, min_spread_eur_kwh=0.0,
+_verdict = PLAN.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=0.0,
                           uncertainty=frozenset())
 check("the point matched for the buy hour IS the verdict's own cheapest point, "
       "by identity - which is why `_act`'s provisional guard is unreachable "
@@ -1688,6 +1679,14 @@ print("4b. §10.2 hysteresis - a price on the boundary cannot flap at 30 s")
 # threshold repeatedly, hour to hour, which is the shape that makes a
 # per-tick price-vs-threshold comparison flap.
 FLAP = [0.20 + (0.101 if i % 2 else 0.0) for i in range(24)]
+# PRICE-02: the verdict skips periods that have ended, and this day had ties
+# (0.20 at every even hour, 0.301 at every odd one). With ties the first hour
+# still ahead is the extreme, so the verdict moves on every hour - once per
+# hour, never per tick, which test_price02.py part 6 grades. This check is
+# about a verdict that stays put while the prices keep crossing the threshold,
+# so the day gets one cheapest and one dearest hour at its end (22: 0.60,
+# 23: 0.05), unique and ahead of every probe until they come.
+FLAP[22], FLAP[23] = 0.60, 0.05
 _flap_plan = plan_of(FLAP)
 check("the flapping fixture really does straddle the threshold hour by hour - "
       "every neighbouring pair differs by more than it",
@@ -1705,7 +1704,7 @@ check(f"over {len(_ticks)} ticks of a day whose price crosses the threshold "
       f"every hour, the strategy changes what it is doing {_transitions} "
       f"times - not once per tick, because the decision is 'which HOUR is "
       f"this', and an hour is 3600 s wide",
-      _transitions <= 24)
+      _transitions <= 4)
 check("...and it is not zero, so the bound above is a bound on a strategy that "
       "acted rather than on one that did nothing",
       _transitions > 0 and CHARGE in _ticks and DISCHARGE in _ticks)
@@ -1862,18 +1861,22 @@ CAP_WH = 10000.0            # the pack the replay moves energy through
 STEP_PCT = 100.0 * MAX_W / CAP_WH    # one hour at the rail, in percent
 
 
-TRADE_HOURS = []            # (day, hour) the strategy acted in (PRICE-02)
-
-
 def replay(threshold, unc, *, soc0=50.0, floor=20.0, ceiling=95.0):
     """Run `decide()` over a synthetic year. Returns the ledger, nothing else."""
     soc = soc0
     trades, holdings, bad = [], [], []
     neg_sells = 0
-    TRADE_HOURS.clear()
     for n in range(365):
         day0 = REPLAY_START + timedelta(days=n)
-        prices = synth_day(n)
+        # PRICE-02: no two hours share a price. The synthetic day is
+        # symmetric, so it prints the same maximum twice; the verdict now takes
+        # the first one still AHEAD, where it used to take the first of the
+        # day (a tie, graded on its own in test_price02.py part 6). So the
+        # ties are broken by a jitter of at most 5e-5 EUR/kWh that has no
+        # direction: not later-is-dearer, which would send every day to a
+        # buy-then-sell and hide the selectivity this replay checks.
+        prices = [round(p + 1e-6 * ((37 * h + 101 * n) % 50), 6)
+                  for h, p in enumerate(synth_day(n))]
         plan = plan_of(prices, start=day0)
         open_buy = None
         for h in range(24):
@@ -1881,7 +1884,6 @@ def replay(threshold, unc, *, soc0=50.0, floor=20.0, ceiling=95.0):
                     ceiling=ceiling, start=day0)
             if d.action is None:
                 continue
-            TRADE_HOURS.append((n, h))
             price = prices[h]
             if d.action == CHARGE:
                 soc = min(ceiling, soc + STEP_PCT)
@@ -1910,12 +1912,9 @@ check(f"the replay is 365 days long and actually traded ({len(_trades)} "
 check("...and every trade carries the spread and the threshold it cleared, so "
       "the ledger is auditable rather than a count",
       _bad == [])
-# PRICE-02: the plan now rolls with the clock, so a day can hold several round
-# trips and every day may trade once. Selective is judged per hour instead.
-check(f"...and the strategy acted in {len(TRADE_HOURS)} of {365 * 24} hours, a "
-      f"minority, so it is selective rather than unconditional - a replay in "
-      f"which everything trades grades nothing",
-      0 < len(TRADE_HOURS) < 365 * 24 // 4)
+check("...and NOT every day traded, so the strategy is selective rather than "
+      "unconditional - a replay in which everything trades grades nothing",
+      len(_trades) < 365)
 _losses = [(b, s) for b, s, _ in _trades if s - b < 0.05]
 check(f"EVERY completed round trip cleared the threshold it was run at: sell "
       f"minus buy >= 0.05 EUR/kWh on all {len(_trades)} of them "
@@ -2475,7 +2474,7 @@ check("...and every one of its points is provisional, so firm_points() is "
       "a fresh observation",
       isinstance(_t12_fb, TariffPlan) and _t12_fb.provisional is True
       and _t12_fb.firm_points() == ()
-      and _t12_fb.arbitrage(peak_guard_active=False, min_spread_eur_kwh=0.0,
+      and _t12_fb.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=0.0,
                             uncertainty=NO_WEATHER).kind == "refused")
 _t12_f.tariff_plan, _t12_f.tariff_at = _t12_good, datetime.now(UTC) - \
     timedelta(seconds=1800)
@@ -2820,7 +2819,7 @@ check(f"the shipped rule and this one give DIFFERENT points at both probes - "
 
 print()
 print("10b. the buy/sell identity test matches the actual extremum interval")
-_qv = QPLAN.arbitrage(peak_guard_active=False, min_spread_eur_kwh=_shipped,
+_qv = QPLAN.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=_shipped,
                       uncertainty=NO_WEATHER)
 check("the verdict's cheapest and dearest are the two QUARTERS, not the hours "
       "containing them - `static_tariff` reduces over every firm point and "
@@ -2952,7 +2951,7 @@ check(f"...and its firm half's extremes are quarters {_mix_cheap_i} and "
       f"{_mix_dear_i}, neither on a whole hour, so the identity test below is "
       f"about the quarter and not about the hour",
       (_mix_cheap_i - MIX_N_H) % 4 != 0 and (_mix_dear_i - MIX_N_H) % 4 != 0)
-_mv = MIX_PLAN.arbitrage(peak_guard_active=False, min_spread_eur_kwh=_shipped,
+_mv = MIX_PLAN.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=_shipped,
                          uncertainty=NO_WEATHER)
 _mix_buy_t = qprobe(_mix_cheap_i, gaps=MIX_GAPS)
 _mix_sell_t = qprobe(_mix_dear_i, gaps=MIX_GAPS)
@@ -2964,14 +2963,19 @@ check("the verdict over a MIXED series still names firm quarters, and "
       is MIX_PTS[_mix_cheap_i]
       and derived(lambda: _arb._point_at(MIX_PLAN, _mix_sell_t))
       is MIX_PTS[_mix_dear_i])
+# PRICE-02: the same day twice, as a running site holds 24-48 h (see plan_of).
+# The probes stay in day one and keep their extremes: once the cheap quarter is
+# over, the verdict at the dear quarter needs a cheap one still ahead.
+MIX2_PLAN = qplan_of(MIX_PRICES * 2, provisional=MIX_FLAGS * 2,
+                     gaps=MIX_GAPS + [900] + MIX_GAPS)
 check("...so the mixed day CHARGES and DISCHARGES in its firm quarters, at "
       "their own prices",
-      decide(MIX_PLAN, _mix_buy_t, peak_guard_active=False, soc=50.0,
+      decide(MIX2_PLAN, _mix_buy_t, peak_guard_active=False, soc=50.0,
              min_spread_eur_kwh=_shipped, uncertainty=NO_WEATHER,
              charge_headroom_w=HEADROOM_CLEAR,
                 charge_w=MAX_W, discharge_w=MAX_W, soc_floor_pct=20.0,
              soc_ceiling_pct=95.0).action == CHARGE
-      and decide(MIX_PLAN, _mix_sell_t, peak_guard_active=False, soc=50.0,
+      and decide(MIX2_PLAN, _mix_sell_t, peak_guard_active=False, soc=50.0,
                  min_spread_eur_kwh=_shipped, uncertainty=NO_WEATHER,
                  charge_headroom_w=HEADROOM_CLEAR,
                 charge_w=MAX_W, discharge_w=MAX_W, soc_floor_pct=20.0,
diff --git a/goodwe_controller/test_home.py b/goodwe_controller/test_home.py
index 8a00330..249c653 100644
--- a/goodwe_controller/test_home.py
+++ b/goodwe_controller/test_home.py
@@ -264,7 +264,7 @@ check("trading on price: a charge block at the cheapest hour (13:00) and a "
 check("...placed where the control cycle's own verdict puts them: the same "
       "plan.arbitrage() call on the same plan",
       c_arb.fresh_tariff_plan(NOW).arbitrage(
-          peak_guard_active=False, min_spread_eur_kwh=0.05,
+          now=NOW, peak_guard_active=False, min_spread_eur_kwh=0.05,
           uncertainty=frozenset({__import__("app.price", fromlist=["x"])
                                  .Uncertainty.NO_WEATHER}))
       .match(allowed=lambda v: (v.cheapest.start, v.dearest.start),
@@ -717,7 +717,7 @@ def _dn(arb):
 
 _c_off, _p_off = _dn(False)
 _c_on, _p_on = _dn(True)
-_v_on, _why_on = homeview.trade_verdict(_c_on, _c_on.fresh_tariff_plan(NOW))
+_v_on, _why_on = homeview.trade_verdict(_c_on, _c_on.fresh_tariff_plan(NOW), NOW)
 check("UX-45: day/night tariff with the stored plan and price trading off: "
       "24 bars, no cheap or dear mark",
       len(_p_off) == 24 and {b["kind"] for b in _p_off} == {"mid"})
diff --git a/goodwe_controller/test_modes_p3.py b/goodwe_controller/test_modes_p3.py
index cd14088..ecb13cd 100644
--- a/goodwe_controller/test_modes_p3.py
+++ b/goodwe_controller/test_modes_p3.py
@@ -67,27 +67,53 @@ A, B = "inverter-a", "inverter-b"
 # ============================================================================ #
 print("1. modes off: byte-identical to 7a00f12 on the trade path")
 # Printed on release/1.0 7a00f12 (2026-09-29), goodwe-addon-checks:1, 1080
-# cycles each; the trade CHARGEs and DISCHARGEs. PRICE-02 (2026-10-22): the
-# digest is `ident.trade_digest()`, which hides two things in the trade
-# sentence: the "above the cheapest" figure (the plan now drops price periods
-# that have ended, so it is another number once the first cheap period is
-# over) and "hour" -> "price period". Re-measured with it on 7a00f12, on
-# release/1.0 90bc901 and on this tree: the same four digests.
+# cycles each; the trade CHARGEs and DISCHARGEs.
+#
+# PRICE-02 (2026-10-22) changed two things in the trade sentence and nothing
+# else: the plan now drops price periods that have ended, so a sale's "N above
+# the cheapest" is another number once the first cheap period is over, and the
+# sentences say "price period" for "hour". So there are three pins:
+#   AT_7A00F12_OLD  the digests printed on 7a00f12, sentence included. They no
+#                   longer match, and the check below says so: that is what
+#                   makes the mask necessary.
+#   AT_7A00F12      the same rows through `ident.trade_digest()`, which hides
+#                   exactly those two things (and only for this comparison with
+#                   an older tree). It equals what 7a00f12 gives through it.
+#   AT_NOW          this tree's own digests, sentence included, with nothing
+#                   hidden: any later change to a command, a sentence or a
+#                   figure moves it. The mask cannot hide a future drift.
+AT_7A00F12_OLD = {
+    "n1": "71245b227ca40bada4f71f57ea6154475f4b0bd60239c9ad4f80bffb0094514c",
+    "n2": "56cf28010b06765c29e5479abb815d7503d570b39240d82dfc818efa90c93722",
+}
 AT_7A00F12 = {
     "n1": "33886ef03f364852883f0370230e6e04823fbb46a4704f88ca75bf9082d98c01",
     "n2": "666a31f41491c22750720524853d95944d5fba395d1d14040c460d71414b275f",
     "n1_off": "33886ef03f364852883f0370230e6e04823fbb46a4704f88ca75bf9082d98c01",
     "n2_off": "666a31f41491c22750720524853d95944d5fba395d1d14040c460d71414b275f",
 }
+AT_NOW = {
+    "n1": "939b3d47bbd64fa50e3d70538f092fb98e5c4bd5ead85a7fc696a1dbb514039e",
+    "n2": "c51008213dd739e1e5142c236d9a950aa585992393e4af120086f1ba52ff3e0d",
+    "n1_off": "939b3d47bbd64fa50e3d70538f092fb98e5c4bd5ead85a7fc696a1dbb514039e",
+    "n2_off": "c51008213dd739e1e5142c236d9a950aa585992393e4af120086f1ba52ff3e0d",
+}
 _cmd_digest = ident.trade_digest
 _rows = {k: ident.run(**ident.SCENARIOS[k])[0] for k in AT_7A00F12}
 _got = {k: _cmd_digest(v) for k, v in _rows.items()}
 for k in AT_7A00F12:
     print(f"    {k} {'same' if _got[k] == AT_7A00F12[k] else 'DIFFERS'} "
           f"{_got[k][:16]}")
+_full = {k: ident.digest(v) for k, v in _rows.items()}
 check("with battery modes off (option absent or false), every command, "
-      "integrator, allocation and trade sentence equals 7a00f12's, at one "
-      "inverter and at two", _got == AT_7A00F12)
+      "integrator, allocation and trade action equals 7a00f12's, at one "
+      "inverter and at two (the sentence masked as above)",
+      _got == AT_7A00F12)
+check("...the mask is needed and nothing more: unmasked, n1 and n2 differ "
+      "from 7a00f12's printed digests, and unmasked they equal this tree's "
+      "own pins, so a later change to any sentence or figure fails here",
+      all(_full[k] != AT_7A00F12_OLD[k] for k in AT_7A00F12_OLD)
+      and _full == AT_NOW)
 _acts = {r[-1][0] for r in _rows["n2"] if r[-1]}
 check("...and the runs reach the trade P3 now skips with modes on: a charge "
       "and a sale", {arbitrage.CHARGE, arbitrage.DISCHARGE} <= _acts)
diff --git a/goodwe_controller/test_price.py b/goodwe_controller/test_price.py
index f8449be..0cd2da4 100644
--- a/goodwe_controller/test_price.py
+++ b/goodwe_controller/test_price.py
@@ -99,6 +99,11 @@ from app.static_tariff import (
     TariffPlan, parse_taxes_profile, static_status)
 from app.validate import validate_startup_config
 
+
+# PRICE-02: `TariffPlan.arbitrage(now=...)` is required. This instant is before every
+# point these fixtures build, so no period has ended and the whole series counts.
+from datetime import datetime as _DT, timezone as _TZ  # noqa: E402
+LONG_AGO = _DT(2000, 1, 1, tzinfo=_TZ.utc)
 fails = []
 
 
@@ -4518,8 +4523,8 @@ _T11_FLAT = TariffPlan(
         [PricePoint(_T11_NOW + timedelta(minutes=15 * i), 0.10, False)
          for i in range(96)],
         PriceProduct.DAY_AHEAD, "generic_dayahead", _T11_NOW), None, "provider")
-_r83 = derived(lambda: _T11_ONEFIRM.arbitrage(**_T11_A9).reason)
-_rflat = derived(lambda: _T11_FLAT.arbitrage(**_T11_A9).reason)
+_r83 = derived(lambda: _T11_ONEFIRM.arbitrage(now=LONG_AGO, **_T11_A9).reason)
+_rflat = derived(lambda: _T11_FLAT.arbitrage(now=LONG_AGO, **_T11_A9).reason)
 print(f"    §8.3 refusal : {_r83[:118]}")
 print(f"    flat refusal : {_rflat[:118]}")
 # 96 quarter-hourly points span 24 hours; ONE firm point spans one of them.
@@ -4828,7 +4833,7 @@ def _t17_verdict(points):
     read = PriceRead.series(points, PriceProduct.DAY_AHEAD, "t17",
                             datetime.now(UTC))
     plan = TariffPlan(read, None, "provider")
-    return plan.arbitrage(peak_guard_active=False,
+    return plan.arbitrage(now=LONG_AGO, peak_guard_active=False,
                           min_spread_eur_kwh=PRICE_OPTION_DEFAULTS[
                               "cycle_cost_threshold_eur"],
                           uncertainty=frozenset())
diff --git a/goodwe_controller/test_price02.py b/goodwe_controller/test_price02.py
index b265234..6ceb4b0 100644
--- a/goodwe_controller/test_price02.py
+++ b/goodwe_controller/test_price02.py
@@ -16,7 +16,12 @@ The trading verdict is taken over the price periods that have not ended.
    point that is still current stays in.
 4. Modes on: a spread that exists only because of an ended period no longer
    opens the gate (`Controller._mode_roles`), nor the Home page verdict.
-5. The reason text says "price period".
+5. The reason text says "price period"; `now` is required (no default).
+6. Ties. The verdict takes the first extreme still ahead, where it used to
+   take the first of the whole plan. On hour-constant 15-minute data (four
+   equal quarters) that is four acting periods in the cheap hour, not one;
+   the number of times the action changes does not grow. The same on a real
+   15-minute day, and hourly alternating prices change at most once an hour.
 
 Mutations: MUTATION.md says how to run them (purged copies); the ones of
 PRICE-02 are listed in the pull request.
@@ -50,6 +55,7 @@ def check(name, cond):
 
 
 UTC = timezone.utc
+LONG_AGO = datetime(2000, 1, 1, tzinfo=UTC)     # before every point: nothing has ended, the old reach
 NO_WEATHER = frozenset({Uncertainty.NO_WEATHER})
 D0 = datetime(2026, 10, 20, 0, 0, tzinfo=UTC)      # 02:00 Brussels
 H3 = D0 + timedelta(hours=1)                       # 03:00 Brussels
@@ -64,6 +70,10 @@ def qplan(prices, start=D0, minutes=15, product=PriceProduct.DAY_AHEAD):
                                        start), None, "provider")
 
 
+ARGS_NO_NOW = dict(ARGS)
+ARGS5 = dict(ARGS, min_spread_eur_kwh=0.05, uncertainty=frozenset())
+
+
 def dec(plan, now, **kw):
     base = dict(peak_guard_active=False, charge_headroom_w=5000.0, soc=50.0,
                 min_spread_eur_kwh=0.10, uncertainty=frozenset(),
@@ -115,9 +125,9 @@ for mins, q in want_q.items():
           and abs(d.price_now_eur_kwh - BUY[q]) < 1e-9)
 check("before the change the same plan at 03:20 aimed at 03:00 (the "
       "verdict without `now`) and decide() did nothing - the defect, shown",
-      BUY_PLAN.arbitrage(**ARGS).cheapest.start == H3
+      BUY_PLAN.arbitrage(now=LONG_AGO, **ARGS).cheapest.start == H3
       and arbitrage._act(BUY_PLAN, H3 + timedelta(minutes=20),
-                         BUY_PLAN.arbitrage(**ARGS), 50.0, 2500.0, 2500.0,
+                         BUY_PLAN.arbitrage(now=LONG_AGO, **ARGS), 50.0, 2500.0, 2500.0,
                          10.0, 90.0, 5000.0).action is None)
 
 # A cheapest period still AHEAD stays the target from every probe.
@@ -186,7 +196,7 @@ same = True
 for m in (0, 5, 20, 35, 59):
     now = H3 + timedelta(minutes=m)
     a = HR_PLAN.arbitrage(now=now, **ARGS)
-    b = HR_PLAN.arbitrage(**ARGS)
+    b = HR_PLAN.arbitrage(now=LONG_AGO, **ARGS)
     same = same and a.cheapest is b.cheapest and a.dearest is b.dearest \
         and a.spread_eur_kwh == b.spread_eur_kwh
 check("an hourly point that is still current stays in: at 03:00, :05, :20, "
@@ -210,7 +220,7 @@ for h in range(0, 24):
         now = D0 + timedelta(hours=h - 2, minutes=m)   # from 22:00 UTC the day before
         plan = static_plan(OPTS, now, now + timedelta(hours=48), now=now)
         a = plan.arbitrage(now=now, **ARGS)
-        b = plan.arbitrage(**ARGS)
+        b = plan.arbitrage(now=LONG_AGO, **ARGS)
         n_checked += 1
         ok = ok and a.kind == b.kind == "allowed" and a.cheapest is b.cheapest \
             and a.dearest is b.dearest and a.spread_eur_kwh == b.spread_eur_kwh
@@ -226,7 +236,7 @@ GATE_PLAN = qplan(GATE)
 now = H3 + timedelta(minutes=20)
 check("the fixture: with the ended 03:00 period in view the verdict is "
       "allowed; from 03:20 on the rest of the series is flat",
-      GATE_PLAN.arbitrage(**ARGS).kind == "allowed"
+      GATE_PLAN.arbitrage(now=LONG_AGO, **ARGS).kind == "allowed"
       and GATE_PLAN.arbitrage(now=now, **ARGS).kind == "refused"
       and "flat" in GATE_PLAN.arbitrage(now=now, **ARGS).reason)
 
@@ -306,6 +316,22 @@ check("...and so do the full-pack and empty-pack sentences ('buy period', "
       "'sell period')",
       "the buy period is here" in _hi.reason
       and "the sell period is here" in _lo.reason)
+import inspect                                                  # noqa: E402
+
+_par = inspect.signature(TariffPlan.arbitrage).parameters
+check("`now` is required: keyword-only with no default, like the three "
+      "arguments beside it, so a caller that forgets it fails loudly instead "
+      "of getting the elapsed periods back",
+      _par["now"].default is inspect.Parameter.empty
+      and _par["now"].kind is inspect.Parameter.KEYWORD_ONLY
+      and all(p.default is inspect.Parameter.empty
+              for n, p in _par.items() if n != "self"))
+try:
+    BUY_PLAN.arbitrage(**ARGS_NO_NOW)
+    _forgot = False
+except TypeError:
+    _forgot = True
+check("...and calling without it raises TypeError", _forgot)
 try:
     BUY_PLAN.arbitrage(now=datetime(2026, 10, 20, 3, 20), **ARGS)
     _naive = False
@@ -314,6 +340,88 @@ except TypeError as e:
 check("a naive `now` is refused: it is ambiguous for one hour every October",
       _naive)
 
+
+# --------------------------------------------------------------------------- #
+print("\n6. ties: the first extreme still ahead")
+def acts(plan, instants, ago=False, args=ARGS):
+    out = []
+    for t in instants:
+        v = plan.arbitrage(now=LONG_AGO if ago else t, **args)
+        d = arbitrage._act(plan, t, v, 50.0, 2500.0, 2500.0, 10.0, 90.0,
+                           5000.0) if v.kind == "allowed" else None
+        out.append(None if d is None else d.action)
+    return out
+
+
+# Hour-constant 15-minute data: the cheap hour is four equal quarters.
+HC = [round(0.40 - 0.0001 * i, 4) for i in range(192)]   # falling, no ties
+for q in range(4, 8):
+    HC[q] = 0.05                        # 03:00-04:00 four equal quarters
+HC[68:72] = [0.50] * 4                  # 19:00-20:00 four equal quarters
+HC_PLAN = qplan(HC)
+probe = [H3 + timedelta(minutes=m) for m in (5, 20, 35, 50, 65)]
+old = acts(HC_PLAN, probe, ago=True)
+new = acts(HC_PLAN, probe)
+check(f"before: four equal cheap quarters, the verdict is the first of them, "
+      f"so the trade acts in one quarter ({old})",
+      old == [CHARGE, None, None, None, None])
+check(f"after: the first one still ahead, so it acts in all four and stops "
+      f"with the hour ({new}) - four acting periods for the same hour, one "
+      f"block either way",
+      new == [CHARGE, CHARGE, CHARGE, CHARGE, None])
+changes = lambda a: sum(1 for x, y in zip(a, a[1:]) if x != y)    # noqa: E731
+check("...the action changes the same number of times (one start, one stop)",
+      changes(old) == changes(new) == 1)
+
+# A real 15-minute day, as production runs it: refresh every 30 min from the
+# floored hour, the verdict at 7 min into every period.
+REAL = os.path.join(HERE, "scenarios",
+                    "energy-charts-be-price-2026-09-09_2026-09-10-twoday.json")
+_d = json.load(open(REAL))
+_pts = [PricePoint(brussels(datetime.fromtimestamp(t, UTC)), p / 1000.0, False)
+        for t, p in zip(_d["unix_seconds"], _d["price"])]
+_feed = PriceRead.series(_pts, PriceProduct.DAY_AHEAD, "generic_dayahead",
+                         _pts[0].start)
+_day0 = _pts[0].start.astimezone(UTC)
+
+def real_day(ago):
+    out = []
+    for q in range(96):
+        t = _day0 + timedelta(minutes=15 * q + 7)
+        ref = t.replace(minute=0 if t.minute < 30 else 30, second=0,
+                        microsecond=0)
+        plan = TariffPlan(fill_from_yesterday(
+            _feed, yesterday=PriceRead.no_data("none"), since=ref,
+            until=ref + timedelta(hours=36), stamp=ref), None, "provider")
+        v = plan.arbitrage(now=LONG_AGO if ago else t, **ARGS5)
+        out.append(arbitrage._act(plan, t, v, 50.0, 2500.0, 2500.0, 10.0,
+                                  90.0, 5000.0).action
+                   if v.kind == "allowed" else None)
+    return out
+
+
+r_old, r_new = real_day(True), real_day(False)
+n_old = sum(1 for a in r_old if a)
+n_new = sum(1 for a in r_new if a)
+print(f"    real 15-minute day 2026-09-09: acting periods {n_old} -> {n_new}, "
+      f"action changes {changes(r_old)} -> {changes(r_new)}")
+check("a real 15-minute day (energy-charts, 2026-09-09) does not switch more "
+      "often: the action changes no more often than before",
+      changes(r_new) <= changes(r_old))
+check("...and every period the old verdict acted in is still acted in, with "
+      "the quarters it had lost to the elapsed-period tie added",
+      all(n is not None for o, n in zip(r_old, r_new) if o) and n_new >= n_old)
+
+# Alternating hourly prices (the flapping day): ties everywhere, so the verdict
+# moves on every hour. At most once an hour, never once a tick.
+FL = [0.20 + (0.101 if i % 2 else 0.0) for i in range(24)] * 2
+FL_PLAN = qplan(FL, minutes=60)
+ticks = [acts(FL_PLAN, [D0 + timedelta(seconds=30 * k)], args=ARGS5)[0]
+         for k in range(24 * 120)]
+check(f"alternating hourly prices: {changes(ticks)} action changes over "
+      f"2880 ticks - at most one an hour, not one a tick",
+      changes(ticks) <= 24 and CHARGE in ticks and DISCHARGE in ticks)
+
 print()
 if fails:
     print(f"{len(fails)} FAILED: " + "; ".join(fails))
diff --git a/goodwe_controller/test_price_forecast.py b/goodwe_controller/test_price_forecast.py
index 65d5459..93a1012 100644
--- a/goodwe_controller/test_price_forecast.py
+++ b/goodwe_controller/test_price_forecast.py
@@ -87,6 +87,11 @@ from app.static_tariff import Arbitrage, TariffPlan
 
 UTC = timezone.utc
 HERE = os.path.dirname(os.path.abspath(__file__))
+
+# PRICE-02: `TariffPlan.arbitrage(now=...)` is required. This instant is before every
+# point these fixtures build, so no period has ended and the whole series counts.
+from datetime import datetime as _DT, timezone as _TZ  # noqa: E402
+LONG_AGO = _DT(2000, 1, 1, tzinfo=_TZ.utc)
 fails = []
 
 
@@ -905,7 +910,7 @@ def min_accepted_spread(product, sources, base, provider="generic_dayahead"):
     lo, hi = 0.0, 4.0
     for _ in range(60):
         mid = (lo + hi) / 2
-        v = plan_with_spread(mid, product, provider).arbitrage(
+        v = plan_with_spread(mid, product, provider).arbitrage(now=LONG_AGO,
             peak_guard_active=False, min_spread_eur_kwh=base,
             uncertainty=sources)
         if v.kind == "allowed":
@@ -1013,7 +1018,7 @@ check(f"the fixture is non-degenerate: the whole-series spread "
       f"{_all_spread:.6f} and the firm-only spread {_firm_spread:.6f} are "
       f"different numbers, so a verdict can be traced to one of them",
       not near(_all_spread, _firm_spread, 1e-6))
-_v = derived(lambda: _mixed.arbitrage(peak_guard_active=False,
+_v = derived(lambda: _mixed.arbitrage(now=LONG_AGO, peak_guard_active=False,
                                       min_spread_eur_kwh=0.0,
                                       uncertainty=frozenset()))
 check("a PART-published series still allows arbitrage - §8.3 forbids acting on "
@@ -1032,7 +1037,7 @@ check("...and it reports the threshold it cleared and why, rather than leaving "
 _all_prov = TariffPlan(PriceRead.series(_cheap_stale, PriceProduct.DAY_AHEAD,
                                         "generic_dayahead", D0), None,
                        "fallback")
-_vp = derived(lambda: _all_prov.arbitrage(peak_guard_active=False,
+_vp = derived(lambda: _all_prov.arbitrage(now=LONG_AGO, peak_guard_active=False,
                                           min_spread_eur_kwh=0.0,
                                           uncertainty=frozenset()))
 check("a WHOLLY provisional series - the §11.4 fallback, or a day before any "
@@ -1046,23 +1051,23 @@ _one_firm = TariffPlan(
                      "generic_dayahead", D0), None, "provider")
 check("one firm hour is not enough either: a buy hour and a sell hour must "
       "BOTH be published before a cycle can be committed",
-      _one_firm.arbitrage(peak_guard_active=False, min_spread_eur_kwh=0.0,
+      _one_firm.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=0.0,
                           uncertainty=frozenset()).kind == "refused")
 check("§10.1 still holds above all of it: the peak guard refuses the same "
       "series that is otherwise allowed",
-      _mixed.arbitrage(peak_guard_active=True, min_spread_eur_kwh=0.0,
+      _mixed.arbitrage(now=LONG_AGO, peak_guard_active=True, min_spread_eur_kwh=0.0,
                        uncertainty=frozenset()).kind == "refused")
 check("the three questions cannot be skipped: all of peak_guard_active, "
       "min_spread_eur_kwh and uncertainty are required and keyword-only",
-      raises(lambda: _mixed.arbitrage(peak_guard_active=False), TypeError)
-      and raises(lambda: _mixed.arbitrage(peak_guard_active=False,
+      raises(lambda: _mixed.arbitrage(now=LONG_AGO, peak_guard_active=False), TypeError)
+      and raises(lambda: _mixed.arbitrage(now=LONG_AGO, peak_guard_active=False,
                                           min_spread_eur_kwh=0.0), TypeError)
       and raises(lambda: _mixed.arbitrage(False, 0.0, frozenset()), TypeError))
 check("...nor answered with a truthy 'unknown' or a negative threshold",
-      raises(lambda: _mixed.arbitrage(peak_guard_active=None,
+      raises(lambda: _mixed.arbitrage(now=LONG_AGO, peak_guard_active=None,
                                       min_spread_eur_kwh=0.0,
                                       uncertainty=frozenset()), TypeError)
-      and raises(lambda: _mixed.arbitrage(peak_guard_active=False,
+      and raises(lambda: _mixed.arbitrage(now=LONG_AGO, peak_guard_active=False,
                                           min_spread_eur_kwh=-0.1,
                                           uncertainty=frozenset()), TypeError))
 
diff --git a/goodwe_controller/test_price_history.py b/goodwe_controller/test_price_history.py
index 8e4a743..33827f9 100644
--- a/goodwe_controller/test_price_history.py
+++ b/goodwe_controller/test_price_history.py
@@ -118,6 +118,11 @@ from app.static_tariff import resolve_tariff
 
 UTC = timezone.utc
 HERE = os.path.dirname(os.path.abspath(__file__))
+
+# PRICE-02: `TariffPlan.arbitrage(now=...)` is required. This instant is before every
+# point these fixtures build, so no period has ended and the whole series counts.
+from datetime import datetime as _DT, timezone as _TZ  # noqa: E402
+LONG_AGO = _DT(2000, 1, 1, tzinfo=_TZ.utc)
 fails = []
 _tmpdirs = []
 
@@ -699,8 +704,8 @@ check(f"the short answer stays a SERIES of what exists - {_pre.read.kind}, "
 # --- the trade set, which is where the whole thing lands ------------------- #
 _A9 = dict(peak_guard_active=False, min_spread_eur_kwh=0.0,
            uncertainty=frozenset())
-_v2 = _pub.arbitrage(**_A9)
-_v1 = _pre.arbitrage(**_A9)
+_v2 = _pub.arbitrage(now=LONG_AGO, **_A9)
+_v1 = _pre.arbitrage(now=LONG_AGO, **_A9)
 check("both plans still ALLOW a trade, so the two verdicts below are compared "
       "against each other and not against a refusal",
       _v2.kind == "allowed" and _v1.kind == "allowed")
@@ -744,8 +749,8 @@ print("2. AC2 - the spread stopped being taken over hours that have gone")
 
 _A = dict(peak_guard_active=False, min_spread_eur_kwh=0.0,
           uncertainty=frozenset())
-_v_before = _before.arbitrage(**_A)
-_v_after = _after.arbitrage(**_A)
+_v_before = _before.arbitrage(now=LONG_AGO, **_A)
+_v_after = _after.arbitrage(now=LONG_AGO, **_A)
 check("both plans still ALLOW a trade, so this section compares two verdicts "
       "rather than a verdict and a refusal",
       _v_before.kind == "allowed" and _v_after.kind == "allowed")
@@ -843,7 +848,7 @@ check("...and no two of them share a whole hour by accident: the fixture puts "
 
 _q_spread_want = round(max(p.eur_per_kwh for p in _q_win)
                        - min(p.eur_per_kwh for p in _q_win), 6)
-_qv = _q_after.arbitrage(**_A)
+_qv = _q_after.arbitrage(now=LONG_AGO, **_A)
 _q_spread_got = _qv.match(allowed=lambda v: v.spread_eur_kwh,
                           refused=lambda _v: None)
 check(f"...and the spread is the fixture's own max - min over that window "
diff --git a/goodwe_controller/test_price_run_fixes.py b/goodwe_controller/test_price_run_fixes.py
index 4e4a191..b98a04c 100644
--- a/goodwe_controller/test_price_run_fixes.py
+++ b/goodwe_controller/test_price_run_fixes.py
@@ -599,26 +599,50 @@ print("\n5. modes off: byte-identical to release/1.0 e3e4ba6")
 # Printed on release/1.0 e3e4ba6 (2026-10-13), goodwe-addon-checks:1, with this
 # branch's harness (same API). n1 and n2 are also 5a4cdc2's; the lag ones moved
 # with SAFETY-90/91 (n2_lag now equals n2: the next-quarter grading removed the
-# edge tick's blindness at N=2). PRICE-02 (2026-10-22): the digest is
-# `ident.trade_digest()`, which hides two things in the trade sentence: the
-# "above the cheapest" figure (the plan now drops price periods that have
-# ended) and "hour" -> "price period". Re-measured with it on e3e4ba6, on
-# release/1.0 90bc901 and on this tree: the same four digests.
+# edge tick's blindness at N=2).
+#
+# PRICE-02 (2026-10-22) changed two things in the trade sentence and nothing
+# else (see test_modes_p3.py part 1): the "N above the cheapest" figure of a
+# sale and "hour" -> "price period". Three pins, as there:
+#   AT_BASE_OLD  the digests printed on e3e4ba6, sentence included (no longer
+#                matched: the mask is needed);
+#   AT_BASE      the same rows through `ident.trade_digest()`, equal to what
+#                e3e4ba6 gives through it;
+#   AT_NOW       this tree's own digests with nothing hidden.
+AT_BASE_OLD = {
+    "n1": "71245b227ca40bada4f71f57ea6154475f4b0bd60239c9ad4f80bffb0094514c",
+    "n2": "56cf28010b06765c29e5479abb815d7503d570b39240d82dfc818efa90c93722",
+    "n1_lag": "86ef0f5ad8da1498ff7dcf59262a177bef847a0b201ce804e947c8eab5f07190",
+    "n2_lag": "56cf28010b06765c29e5479abb815d7503d570b39240d82dfc818efa90c93722",
+}
 AT_BASE = {
     "n1": "33886ef03f364852883f0370230e6e04823fbb46a4704f88ca75bf9082d98c01",
     "n2": "666a31f41491c22750720524853d95944d5fba395d1d14040c460d71414b275f",
     "n1_lag": "f6c67b351bd732fb69e62cafbfdb2bcff6032f5d8845836659d096b8c677d3c0",
     "n2_lag": "666a31f41491c22750720524853d95944d5fba395d1d14040c460d71414b275f",
 }
+AT_NOW = {
+    "n1": "939b3d47bbd64fa50e3d70538f092fb98e5c4bd5ead85a7fc696a1dbb514039e",
+    "n2": "c51008213dd739e1e5142c236d9a950aa585992393e4af120086f1ba52ff3e0d",
+    "n1_lag": "78aac892975be81a7ceac0c000ed441a731bd4f42ff9f729996cbee53d6b7f02",
+    "n2_lag": "c51008213dd739e1e5142c236d9a950aa585992393e4af120086f1ba52ff3e0d",
+}
 _cmd_digest = ident.trade_digest
-_got = {k: _cmd_digest(ident.run(**ident.SCENARIOS[k])[0])
-        for k in AT_BASE}
+_rows5 = {k: ident.run(**ident.SCENARIOS[k])[0] for k in AT_BASE}
+_got = {k: _cmd_digest(v) for k, v in _rows5.items()}
+_full5 = {k: ident.digest(v) for k, v in _rows5.items()}
 for _k in AT_BASE:
     print(f"    {_k} {'same' if _got[_k] == AT_BASE[_k] else 'DIFFERS'} "
           f"{_got[_k][:16]}")
 check("with battery modes off every command, integrator, allocation and "
-      "trade sentence equals e3e4ba6's, also when every quarter boundary's "
-      "cycle still sees the old P1 block", _got == AT_BASE)
+      "trade action equals e3e4ba6's (the sentence masked as above), also when "
+      "every quarter boundary's cycle still sees the old P1 block",
+      _got == AT_BASE)
+check("...the mask is needed and nothing more: unmasked, the digests differ "
+      "from e3e4ba6's printed ones, and equal this tree's own pins, so a "
+      "later change to any sentence or figure fails here",
+      all(_full5[k] != AT_BASE_OLD[k] for k in AT_BASE_OLD)
+      and _full5 == AT_NOW)
 
 _real_project = tariff.PeakTracker.project
 tariff.PeakTracker.project = staticmethod(
diff --git a/goodwe_controller/test_price_service.py b/goodwe_controller/test_price_service.py
index 063337f..bfe94ae 100644
--- a/goodwe_controller/test_price_service.py
+++ b/goodwe_controller/test_price_service.py
@@ -1178,7 +1178,7 @@ async def _modes_plan():
         c = W.ctl
         plan = c.fresh_tariff_plan(t)
         verdict = plan.arbitrage(
-            peak_guard_active=False, min_spread_eur_kwh=0.05,
+            now=t, peak_guard_active=False, min_spread_eur_kwh=0.05,
             uncertainty=frozenset())
         return verdict.match(allowed=lambda v: ("allowed", v.spread_eur_kwh),
                              refused=lambda v: ("refused", v.reason))
diff --git a/goodwe_controller/test_static_tariff.py b/goodwe_controller/test_static_tariff.py
index cc9f2d1..2537ac3 100644
--- a/goodwe_controller/test_static_tariff.py
+++ b/goodwe_controller/test_static_tariff.py
@@ -82,6 +82,11 @@ from app.validate import validate_startup_config
 
 HERE = Path(__file__).resolve().parent
 UTC = timezone.utc
+
+# PRICE-02: `TariffPlan.arbitrage(now=...)` is required. This instant is before every
+# point these fixtures build, so no period has ended and the whole series counts.
+from datetime import datetime as _DT, timezone as _TZ  # noqa: E402
+LONG_AGO = _DT(2000, 1, 1, tzinfo=_TZ.utc)
 fails = []
 
 
@@ -333,8 +338,8 @@ check(f"...while the two-period spread is the day/night difference "
       f"{_spread_two}, re-derived here as {DAY_P - NIGHT_P:.4f}",
       near(_spread_two, DAY_P - NIGHT_P, 1e-9))
 
-_v_fixed = p_fixed.arbitrage(peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset())
-_v_two = p_two.arbitrage(peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset())
+_v_fixed = p_fixed.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset())
+_v_two = p_two.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset())
 check("a fully-fixed tariff REFUSES arbitrage", _v_fixed.kind == "refused")
 check("...for the true reason - the series is flat, so there is nothing to buy "
       "low and sell high, not because a FIXED enum was matched on",
@@ -354,7 +359,7 @@ _flat_dayahead = TariffPlan(
     None, "provider")
 check("a DAY_AHEAD series that happens to be flat is refused too, so the rule "
       "is arithmetic and not a product label",
-      _flat_dayahead.arbitrage(peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "refused")
+      _flat_dayahead.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "refused")
 
 # The numbers an optimiser needs exist ONLY on the permitting variant.
 check("the allowed verdict carries the spread, the cheapest hour and the "
@@ -379,16 +384,16 @@ check("...and there is no falsy variant, so `if verdict:` cannot look like a "
 # §10.1 priority 2 over priority 3, expressed so OPT-04 cannot skip it.
 check("peak shaving outranks arbitrage: the SAME allowed plan is refused when "
       "the peak guard is holding",
-      p_two.arbitrage(peak_guard_active=True, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "refused")
+      p_two.arbitrage(now=LONG_AGO, peak_guard_active=True, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "refused")
 check("...and the reason names the ordering rather than the tariff",
-      "priority 2" in p_two.arbitrage(peak_guard_active=True, min_spread_eur_kwh=0.0, uncertainty=frozenset()).reason)
+      "priority 2" in p_two.arbitrage(now=LONG_AGO, peak_guard_active=True, min_spread_eur_kwh=0.0, uncertainty=frozenset()).reason)
 check("...and the question cannot be skipped: peak_guard_active is required "
       "and keyword-only, so a spread is not obtainable without answering it",
       raises(lambda: p_two.arbitrage(), TypeError)
       and raises(lambda: p_two.arbitrage(False), TypeError))
 check("...nor answered with a truthy 'unknown'",
-      raises(lambda: p_two.arbitrage(peak_guard_active=None), TypeError)
-      and raises(lambda: p_two.arbitrage(peak_guard_active="no"), TypeError))
+      raises(lambda: p_two.arbitrage(now=LONG_AGO, peak_guard_active=None), TypeError)
+      and raises(lambda: p_two.arbitrage(now=LONG_AGO, peak_guard_active="no"), TypeError))
 
 
 # --------------------------------------------------------------------------- #
@@ -524,7 +529,7 @@ check("...and its underlying read has no .points at all, so `min(read.points)` "
       "cannot run against it",
       raises(lambda: _none.read.points, Absence))
 check("...and arbitrage is refused, per §11.4",
-      _none.arbitrage(peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "refused"
+      _none.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "refused"
       and arbitrage_allowed(_none.read) is False)
 check("...and static_status() says so in words rather than reporting a price",
       static_status(opts(None), THU) == (False, "No fixed tariff set"))
@@ -776,12 +781,12 @@ check("...marked PROVISIONAL, which is the one flag that differs",
       _fb.provisional and plan_is_provisional(_fb.read))
 check("...and arbitrage is refused on it, per §11.4, even though a full series "
       "exists and has a real spread",
-      _fb.arbitrage(peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "refused"
+      _fb.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "refused"
       and near(_fb.spread_eur_kwh(), DAY_P - NIGHT_P))
 check("...while the SAME profile as the configured product allows it - so the "
       "refusal is about provisionality and not about the profile",
       static_plan(opts(TWO_PERIOD), THU, THU + timedelta(days=1)
-                  ).arbitrage(peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "allowed")
+                  ).arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "allowed")
 check("...and the provisional plan has no cheap window either: §8.3 forbids an "
       "irreversible action on a provisional price, and a grid top-up is one",
       not any(_fb.cheap_now(at_local(THU, h)) for h in range(24)))
@@ -821,8 +826,8 @@ check("a live feed is used in preference to the static profile",
       and _live_plan.product is PriceProduct.DAY_AHEAD)
 check("...and arbitrage is allowed on it, with the spread derived from the "
       "feed rather than from the profile",
-      _live_plan.arbitrage(peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "allowed"
-      and near(_live_plan.arbitrage(peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).spread_eur_kwh,
+      _live_plan.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).kind == "allowed"
+      and near(_live_plan.arbitrage(now=LONG_AGO, peak_guard_active=False, min_spread_eur_kwh=0.0, uncertainty=frozenset()).spread_eur_kwh,
                0.023, 1e-9))
 
 
@@ -1036,7 +1041,7 @@ check(f"each tiny-spread probe really carries the spread it is named for, and "
       all(near(p.spread_eur_kwh(), d, 1e-12)
           and len([q for q in p.read.points if not q.provisional]) == 2
           for d, p in _tiny9))
-_tinyv9 = [(d, rung9(p.arbitrage(**_A9))) for d, p in _tiny9]
+_tinyv9 = [(d, rung9(p.arbitrage(now=LONG_AGO, **_A9))) for d, p in _tiny9]
 check(f"TEST-16 AC1: a spread that is SMALL BUT REAL is ALLOWED at "
       f"min_spread_eur_kwh=0.0 - down to 0.000001 EUR/kWh, so the flat rung is "
       f"`spread == 0.0` and not `spread <= epsilon` for any epsilon "
@@ -1045,7 +1050,7 @@ check(f"TEST-16 AC1: a spread that is SMALL BUT REAL is ALLOWED at "
 check("...and the exactly flat series on the OTHER side of that boundary is "
       "still refused, and refused BY THE FLAT RUNG - without this the sweep "
       "above would also pass for a rung that had been deleted outright",
-      rung9(plan9([0.20000, 0.20000]).arbitrage(**_A9)) == "flat")
+      rung9(plan9([0.20000, 0.20000]).arbitrage(now=LONG_AGO, **_A9)) == "flat")
 _q9 = plan9([0.20000, 0.2000005])
 check(f"...and a difference below the rung's own 6-decimal rounding is flat BY "
       f"CONSTRUCTION and says so: the raw difference is "
@@ -1056,10 +1061,10 @@ check(f"...and a difference below the rung's own 6-decimal rounding is flat BY "
       f"to bisect further",
       not near(_q9.spread_eur_kwh(), 0.0, 1e-9)
       and near(round(_q9.spread_eur_kwh(), 6), 0.0, 1e-12)
-      and rung9(_q9.arbitrage(**_A9)) == "flat")
+      and rung9(_q9.arbitrage(now=LONG_AGO, **_A9)) == "flat")
 
 # --- and what D's survival actually costs: the sentence, not the verdict -----
-_lie9 = plan9([0.20000, 0.20050]).arbitrage(**_A9)
+_lie9 = plan9([0.20000, 0.20050]).arbitrage(now=LONG_AGO, **_A9)
 check(f"TEST-16 AC4: the 0.0005 verdict carries the real spread rather than a "
       f"flatness claim about a tariff that is not flat - the false sentence is "
       f"what a loosened rung ships to the operator while the outcome at a "
@@ -1085,19 +1090,19 @@ check(f"the one-firm probe is well formed: exactly ONE firm hour out of three, "
 check("TEST-16 AC2: one firm hour is refused BY §8.3's FIRM-PAIR RUNG, named "
       "in the reason - not by the flat rung that would also have refused it. "
       "This is what takes `len(firm) < 2` -> `< 1` red on its own",
-      rung9(_one9.arbitrage(**_A9)) == "firm-pair")
+      rung9(_one9.arbitrage(now=LONG_AGO, **_A9)) == "firm-pair")
 check("...and the sentence is §8.3's in full, so the operator is told the "
       "series is half-published rather than told it is fixed-price",
-      "§8.3" in _one9.arbitrage(**_A9).reason
-      and "only 1 of 3" in _one9.arbitrage(**_A9).reason
-      and "flat" not in _one9.arbitrage(**_A9).reason)
+      "§8.3" in _one9.arbitrage(now=LONG_AGO, **_A9).reason
+      and "only 1 of 3" in _one9.arbitrage(now=LONG_AGO, **_A9).reason
+      and "flat" not in _one9.arbitrage(now=LONG_AGO, **_A9).reason)
 # The rung pinned from ABOVE as well. Without this, `len(firm) < 3` - the same
 # +0 B edit in the other direction - would pass everything above.
 _two9 = plan9([0.20, 0.40, 0.10], [False, False, True])
 check("...and TWO firm hours are ALLOWED on the identical series shape, so the "
       "rung is pinned from above too and `< 3` is red as well as `< 1`",
-      rung9(_two9.arbitrage(**_A9)) == "allowed"
-      and near(_two9.arbitrage(**_A9).spread_eur_kwh, 0.20))
+      rung9(_two9.arbitrage(now=LONG_AGO, **_A9)) == "allowed"
+      and near(_two9.arbitrage(now=LONG_AGO, **_A9).spread_eur_kwh, 0.20))
 # ...and from below, where the failure is not a wrong sentence but a crash:
 # `max()` over an empty `firm` raises ValueError, so `< 0` does not degrade the
 # reason, it takes the verdict away entirely.
@@ -1105,7 +1110,7 @@ _zero9 = plan9([0.20, 0.40, 0.10], [True, True, True])
 check("...and a FULLY provisional series is refused by the same rung and does "
       "not raise - `max()` over an empty firm set is a ValueError, so this row "
       "is what makes `len(firm) < 0` red",
-      rung9(derived(lambda: _zero9.arbitrage(**_A9))) == "firm-pair")
+      rung9(derived(lambda: _zero9.arbitrage(now=LONG_AGO, **_A9))) == "firm-pair")
 
 # --- AC3: the two rungs do not mask each other ------------------------------
 # ⚠️ THE POINT OF THE TICKET, AND IT IS A PROPERTY OF THE TABLE, NOT OF A ROW.
@@ -1130,7 +1135,7 @@ _TABLE9 = (
     ("two firm hours of three", _two9, "allowed"),
     ("no firm hours at all", _zero9, "firm-pair"),
 )
-_got9 = [(name, want, rung9(derived(lambda p=pl: p.arbitrage(**_A9))))
+_got9 = [(name, want, rung9(derived(lambda p=pl: p.arbitrage(now=LONG_AGO, **_A9))))
          for name, pl, want in _TABLE9]
 check(f"TEST-16 AC3: each stimulus is answered by the rung that OWNS it, and "
       f"by no other - the flat rung is asked a question the firm-pair rung "
diff --git a/goodwe_controller/tools/opt11p3_identity.py b/goodwe_controller/tools/opt11p3_identity.py
index 78e3d52..fd9760c 100644
--- a/goodwe_controller/tools/opt11p3_identity.py
+++ b/goodwe_controller/tools/opt11p3_identity.py
@@ -123,7 +123,10 @@ def _trade_words(text):
     plan now drops price periods that have ended, so a sale's "above the
     cheapest" figure is a different number once the first cheap period is
     over, and the sentences say "price period" where they said "hour". Both
-    maps are applied to both sides, so only those two things are hidden."""
+    maps are applied to both sides, so only those two things are hidden.
+
+    ONLY FOR COMPARING WITH A TREE OLDER THAN PRICE-02. A pin of this tree
+    itself uses `digest()`, with nothing hidden."""
     text = text.replace("this hour is neither the buy hour nor the sell hour",
                         "now is not the cheapest or the dearest price period")
     text = re.sub(r"[0-9]+\.[0-9]+ above the cheapest",