Long expeditions D2-b: event-anchored day rollover

Splits the legacy briefing body into nightRolloverBurn + nightRolloverDrift,
plus a processNightCamp convenience. For expeditions started after the new
eventAnchoredCutoff, the 06:00 UTC briefing stops mutating: it posts a
re-engagement DM, and only force-fires processNightCamp itself after a 28h
safety-net window. Day++/burn/threat-drift now ride along the autopilot
night-camp pitch (decideAutopilotCamp sets Night=true when ≥16h since the
last rollover) and on the first player !camp since the last rollover. The
legacy UTC-anchored flow still works via the same staged helpers, with
processOvernightCamp interleaved to preserve the rest-before-drift ordering.

Tests pin eventAnchoredCutoff to year 9999 in TestMain so the existing
legacy assertions still run; new tests cover the night decision, the
night-camp pitch advancing the day, the event-anchored skip, and the
safety-net force-rollover.

gogobee_long_expedition_plan.md

@@ -58,6 +58,8 @@ Built across multiple sessions; each phase ships independently with tests and a
 
 **D2-a (shipped 2026-05-27):** new `expedition_autocamp.go` with pure `decideAutopilotCamp` + `pitchAutopilotCamp` + dwell-window lifecycle (`shouldSkipAutoRunForCamp`, `breakAutoCampIfDue`). Wired into `tryAutoRun`: skip while inside `minAutoCampDwell` (4h), break + walk past it, post-walk scheduler pitches HP-low rest camps and region-boss base-camp waypoints. CampState gained `AutoPitched` so auto- vs player-pitched lifetimes diverge. Day rollover is still UTC-anchored; D2-b moves it event-anchored.
 
+**D2-b (shipped 2026-05-27):** event-anchored day rollover. `dnd_expedition_cycle.go` adds `eventAnchoredCutoff` + `isEventAnchored`, splits the briefing body into `nightRolloverBurn` + `nightRolloverDrift` (+ a convenience `processNightCamp` that runs both back-to-back). For expeditions started ≥ cutoff, `deliverBriefing` skips mutators and posts a re-engagement DM; if `last_briefing_at` is older than `nightSafetyNet` (28h) it force-fires `processNightCamp` so a stalled autopilot doesn't freeze the expedition. The autopilot scheduler grew a `Night` flag — `decideAutopilotCamp` sets it when `time.Since(LastBriefingAt) ≥ nightCampWindow` (16h); `pitchAutopilotCamp` then runs the burn → camp → rest → drift sequence in one pitch. Manual `!camp <type>` runs the same flow when it's the first camp since the last rollover. Legacy UTC-anchored expeditions (start_date < cutoff) keep the original mutator flow via the same staged helpers, preserving rest-before-drift ordering through `processOvernightCamp`. Tests fence cutoff to year 9999 in `TestMain` so existing legacy assertions stand; new tests exercise the night decision, night-pitch rollover, event-anchored skip, and safety-net force.
+
 
 **Files:** new `expedition_autocamp.go`; hooks in `expedition_autorun.go:tryAutoRun`; reuse `dnd_expedition_camp.go:campPitch` / `applyCampRest`.
 **Heuristics (in priority order):**

internal/plugin/adv2_scenario_test.go

@@ -221,10 +221,9 @@ func TestAdv2Scenario_ExpeditionCryptValdris(t *testing.T) {
 		t.Errorf("expected outfitting to debit coins (%.2f → %.2f)", balBefore, balAfter)
 	}
 
-	// Backdate start so deliverBriefing's same-day guard passes.
+	// Backdate start so deliverBriefing's same-day guard passes, and to
-	if _, err := dbExecExpeditionBackdate(exp.ID, 24*time.Hour); err != nil {
+	// before eventAnchoredCutoff so the legacy mutator path still fires.
-		t.Fatalf("backdate: %v", err)
+	rewindToLegacyAnchor(t, exp)
-	}
 
 	// Drive 3 daily briefings — verify supply burn + day advance.
 	now := time.Date(2026, 5, 8, 6, 0, 0, 0, time.UTC)

internal/plugin/dnd_audit_phase_R7_test.go

@@ -168,9 +168,7 @@ func TestDeliverBriefing_StarvationForcesExtraction(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if _, err := dbExecExpeditionBackdate(exp.ID, 24*time.Hour); err != nil {
+	rewindToLegacyAnchor(t, exp)
-		t.Fatalf("backdate: %v", err)
-	}
 
 	p := &AdventurePlugin{}
 	now := time.Date(2026, 5, 8, 6, 0, 0, 0, time.UTC)

internal/plugin/dnd_expedition_camp.go

@@ -160,6 +160,30 @@ func (p *AdventurePlugin) campPitch(ctx MessageContext, exp *Expedition, kind st
 			cost, exp.Supplies.Current))
 	}
 
+	// D2-b: event-anchored manual !camp counts as the night camp if it's
+	// the first camp since the last rollover. Burn supplies *before* the
+	// camp cost so the burn lands against pre-pitch supplies (matches the
+	// legacy morning-burn ordering), then pitch, then drift.
+	nightCamp := false
+	var nightBurn float32
+	var nightRoll nightRolloverResult
+	if isEventAnchored(exp) {
+		var since time.Duration
+		if exp.LastBriefingAt != nil {
+			since = time.Now().UTC().Sub(*exp.LastBriefingAt)
+		} else {
+			since = time.Now().UTC().Sub(exp.StartDate)
+		}
+		if since >= nightCampWindow {
+			nightCamp = true
+			burn, err := p.nightRolloverBurn(exp)
+			if err != nil {
+				return p.SendDM(ctx.Sender, "Couldn't burn night supplies: "+err.Error())
+			}
+			nightBurn = burn
+		}
+	}
+
 	exp.Supplies.Current -= cost
 	if err := updateSupplies(exp.ID, exp.Supplies); err != nil {
 		return p.SendDM(ctx.Sender, "Couldn't deduct supplies: "+err.Error())
@@ -180,6 +204,10 @@ func (p *AdventurePlugin) campPitch(ctx MessageContext, exp *Expedition, kind st
 	// until the next 06:00 UTC briefing for HP and spell slots to come
 	// back. The flag tells processOvernightCamp not to re-apply at briefing.
 	restSummary := applyCampRest(exp, kind)
+	if nightCamp {
+		nightRoll = p.nightRolloverDrift(exp, time.Now().UTC())
+		nightRoll.Burn = nightBurn
+	}
 	camp.RestApplied = true
 	if err := updateCamp(exp.ID, camp); err != nil {
 		slog.Warn("camp: mark rest applied", "expedition", exp.ID, "err", err)
@@ -221,6 +249,15 @@ func (p *AdventurePlugin) campPitch(ctx MessageContext, exp *Expedition, kind st
 	case CampTypeBase:
 		b.WriteString("\n_Base camp — **waypoint persisted**. Camp here again at no eligibility cost on later returns._")
 	}
+	if nightCamp {
+		b.WriteString(fmt.Sprintf("\n\n🌙 **Day %d.** _Overnight burn: %.1f SU._\n", exp.CurrentDay, nightRoll.Burn))
+		for _, tl := range nightRoll.TemporalLines {
+			b.WriteString("\n🌀 " + tl + "\n")
+		}
+		for _, ml := range nightRoll.MilestoneLines {
+			b.WriteString("\n" + ml)
+		}
+	}
 	return p.SendDM(ctx.Sender, b.String())
 }
 

internal/plugin/dnd_expedition_cycle.go

@@ -32,8 +32,128 @@ import (
 const (
 	expeditionBriefingHour = 6
 	expeditionRecapHour    = 21
+
+	// nightSafetyNet — if an event-anchored expedition's last rollover is
+	// older than this, the 06:00 UTC briefing ticker force-fires
+	// processNightCamp itself. Without this, an expedition whose autopilot
+	// stalled (long combat, missed tick, manual halt) would drift forever
+	// without burning supplies or advancing days. 28h gives the autopilot
+	// 4h of slop past a normal day before we step in.
+	nightSafetyNet = 28 * time.Hour
 )
 
+// eventAnchoredCutoff — expeditions started at or after this timestamp
+// use the D2-b event-anchored day-rollover model: day++/burn/threat-drift
+// fire when the autopilot (or a player !camp) pitches a night camp, and
+// the 06:00 UTC briefing becomes a re-engagement DM with a safety-net
+// force. Expeditions started before this stay on the legacy UTC-anchored
+// briefing rollover until they end.
+var eventAnchoredCutoff = time.Date(2026, 5, 27, 18, 0, 0, 0, time.UTC)
+
+// isEventAnchored — true when this expedition uses the D2-b model.
+func isEventAnchored(e *Expedition) bool {
+	if e == nil {
+		return false
+	}
+	return !e.StartDate.Before(eventAnchoredCutoff)
+}
+
+// nightRolloverResult — the side effects processNightCamp produced, so
+// callers (autopilot pitch, manual !camp, safety-net briefing) can render
+// the same numbers into their own DM block.
+type nightRolloverResult struct {
+	Burn           float32
+	TemporalLines  []string
+	MilestoneLines []string
+	Starved        bool
+}
+
+// nightRolloverBurn — stage 1 of the day rollover: zone temporal pre-burn
+// + daily supply burn + current_day++. Returns the burn applied. Callers
+// follow this with applyCampRest (if pitching) and then nightRolloverDrift
+// to finish the rollover; legacy deliverBriefing interleaves processOvernightCamp
+// between the two so a fortified camp's −5 lands before drift's +3.
+func (p *AdventurePlugin) nightRolloverBurn(e *Expedition) (float32, error) {
+	burnOverride := applyZoneTemporalPreBurn(e, e.CurrentDay+1)
+	var newSupplies ExpeditionSupplies
+	var burn float32
+	if burnOverride.Multiplier > 0 {
+		burn = e.Supplies.DailyBurn * burnOverride.Multiplier * float32(phase5BDailyBurnRatePct) / 100
+		newSupplies = e.Supplies
+		newSupplies.Current -= burn
+		if newSupplies.Current < 0 {
+			newSupplies.Current = 0
+		}
+		newSupplies.ForagedToday = false
+	} else {
+		harsh := e.ThreatLevel > 60 || zoneTemporalHarsh(e)
+		newSupplies, burn = applyDailyBurn(e.Supplies, harsh, e.SiegeMode)
+	}
+	if err := updateSupplies(e.ID, newSupplies); err != nil {
+		return 0, err
+	}
+	if err := advanceExpeditionDay(e.ID); err != nil {
+		return 0, err
+	}
+	e.Supplies = newSupplies
+	e.CurrentDay++
+	return burn, nil
+}
+
+// nightRolloverDrift — stage 2: daily threat drift, zone temporal post-
+// rollover, starvation check, max-threat record, milestones. Stamps
+// last_briefing_at = now so the UTC briefing ticker treats today as
+// already-rolled. `now` is the wallclock to stamp; callers that already
+// did the stamp via a CAS (deliverBriefing) pass time.Time{} to skip.
+func (p *AdventurePlugin) nightRolloverDrift(e *Expedition, now time.Time) nightRolloverResult {
+	var out nightRolloverResult
+	if _, _, err := applyDailyThreatDrift(e); err != nil {
+		slog.Warn("expedition: threat drift", "expedition", e.ID, "err", err)
+	}
+	out.TemporalLines = applyZoneTemporalPostRollover(e)
+
+	if supplyDepletion(e.Supplies) == SupplyStarvation && e.Status == ExpeditionStatusActive {
+		_, _, _ = forcedExtractExpedition(e.ID, "starvation")
+		e.Status = ExpeditionStatusAbandoned
+		line := flavor.Pick(flavor.ExtractionForced)
+		_ = appendExpeditionLog(e.ID, e.CurrentDay, "narrative",
+			"forced extraction: starvation", line)
+		out.Starved = true
+	}
+	if e.Status == ExpeditionStatusAbandoned && p.euro != nil {
+		tax := int(float64(e.CoinsEarned) * forcedExtractCoinTaxFrac)
+		if tax > 0 {
+			p.euro.Debit(id.UserID(e.UserID), float64(tax),
+				"forced extraction tax")
+		}
+	}
+	_ = recordMaxThreat(e)
+	out.MilestoneLines = p.checkDailyMilestones(e)
+
+	if !now.IsZero() {
+		if _, err := db.Get().Exec(`
+			UPDATE dnd_expedition
+			   SET last_briefing_at = ?
+			 WHERE expedition_id = ?`, now, e.ID); err == nil {
+			e.LastBriefingAt = &now
+		}
+	}
+	return out
+}
+
+// processNightCamp — burn + drift in one go, no rest in between. Used by
+// callers (autopilot pitch, manual !camp, event-anchored safety net) that
+// either apply their own rest separately or don't apply one at all.
+func (p *AdventurePlugin) processNightCamp(e *Expedition) (nightRolloverResult, error) {
+	burn, err := p.nightRolloverBurn(e)
+	if err != nil {
+		return nightRolloverResult{}, err
+	}
+	out := p.nightRolloverDrift(e, time.Now().UTC())
+	out.Burn = burn
+	return out, nil
+}
+
 // expeditionBriefingTicker — 06:00 UTC daily briefing.
 func (p *AdventurePlugin) expeditionBriefingTicker() {
 	ticker := time.NewTicker(1 * time.Minute)
@@ -176,14 +296,17 @@ func scanExpeditionRows(rows *sql.Rows) ([]*Expedition, error) {
 	return out, rows.Err()
 }
 
-// deliverBriefing rolls a day forward, applies supply burn, posts the
+// deliverBriefing posts the morning briefing DM. For legacy UTC-anchored
-// morning briefing DM, appends a log entry, and stamps last_briefing_at.
+// expeditions it also drives the day rollover (supply burn, day++, threat
+// drift) via processNightCamp. For event-anchored expeditions (D2-b) the
+// rollover is owned by the autopilot's night-camp pitch; the briefing
+// ticker only re-engages the player and force-fires the rollover after a
+// safety-net window.
 //
-// Idempotency: the first thing we do is an atomic compare-and-set on
+// Idempotency: atomic compare-and-set on last_briefing_at gates the body.
-// last_briefing_at. If another invocation (clock skew, restart, double
+// A double-fire on the same expedition is a no-op.
-// fire) already claimed today's rollover, rowsAffected == 0 and we bail
-// without re-applying supply burn / day++ / threat drift.
 func (p *AdventurePlugin) deliverBriefing(e *Expedition, now time.Time) error {
+	priorBriefing := e.LastBriefingAt
 	threshold := time.Date(now.Year(), now.Month(), now.Day(),
 		expeditionBriefingHour, 0, 0, 0, time.UTC)
 	res, err := db.Get().Exec(`
@@ -200,45 +323,24 @@ func (p *AdventurePlugin) deliverBriefing(e *Expedition, now time.Time) error {
 	if n, _ := res.RowsAffected(); n == 0 {
 		return nil // already delivered for this day
 	}
+	e.LastBriefingAt = &now
 
-	// E3: zone-specific temporal events fire BEFORE applyDailyBurn and
+	// D2-b: event-anchored expeditions own the day rollover via the
-	// can override the entire burn calculation with a fixed multiplier
+	// autopilot night camp. The 06:00 ticker either posts a re-engagement
-	// (Sunken Temple tidal 2.0×, Feywild half-day 0.5×, etc.).
+	// DM (rollover happened recently) or force-fires processNightCamp
-	burnOverride := applyZoneTemporalPreBurn(e, e.CurrentDay+1)
+	// itself (safety net for stalled autopilots).
-
+	if isEventAnchored(e) {
-	// Advance day + supply burn happen together at the morning rollover.
+		return p.deliverBriefingEventAnchored(e, priorBriefing)
-	var newSupplies ExpeditionSupplies
-	var burn float32
-	if burnOverride.Multiplier > 0 {
-		// Phase 5-B: temporal overrides bypass applyDailyBurn, so apply
-		// the same global burn-rate multiplier explicitly here. Without
-		// this, tidal/unraveling days would burn at pre-Phase-5-B rates
-		// while normal days burn at half — an inconsistency the user
-		// would feel as "tidal days are now disproportionately harsh."
-		burn = e.Supplies.DailyBurn * burnOverride.Multiplier * float32(phase5BDailyBurnRatePct) / 100
-		newSupplies = e.Supplies
-		newSupplies.Current -= burn
-		if newSupplies.Current < 0 {
-			newSupplies.Current = 0
-		}
-		newSupplies.ForagedToday = false
-	} else {
-		harsh := e.ThreatLevel > 60 || zoneTemporalHarsh(e)
-		newSupplies, burn = applyDailyBurn(e.Supplies, harsh, e.SiegeMode)
 	}
-	if err := updateSupplies(e.ID, newSupplies); err != nil {
+
+	burn, err := p.nightRolloverBurn(e)
+	if err != nil {
 		return err
 	}
-	if err := advanceExpeditionDay(e.ID); err != nil {
-		return err
-	}
-	e.Supplies = newSupplies
-	e.CurrentDay++
 
-	// E2d: overnight camp rest effects (HP/spells/threat). Auto-breaks
+	// E2d: overnight camp rest. Runs after burn/day++ but before drift so
-	// the camp after applying. Run before threat drift so a fortified
+	// a fortified camp's −5 lands first and a same-day +3 drift can't push
-	// camp's −5 lands first and a same-day +3 drift can't push back over
+	// back over a threshold the rest just dropped.
-	// a threshold the rest just dropped.
 	restSummary := processOvernightCamp(e)
 	if restSummary != "" {
 		if fresh, err := getExpedition(e.ID); err == nil && fresh != nil {
@@ -248,54 +350,20 @@ func (p *AdventurePlugin) deliverBriefing(e *Expedition, now time.Time) error {
 		}
 	}
 
-	// E2a: daily threat drift (+3 base, GM-mood modifier). No-op after
+	// Pass time.Time{} — the CAS at the top of deliverBriefing already
-	// boss kill. May cross a threshold and append a flavor-bearing log.
+	// stamped last_briefing_at with the synthetic now; don't overwrite it.
-	if _, _, err := applyDailyThreatDrift(e); err != nil {
+	roll := p.nightRolloverDrift(e, time.Time{})
-		slog.Warn("expedition: threat drift", "expedition", e.ID, "err", err)
+	roll.Burn = burn
-	}
-
-	// E3: zone temporal events post-rollover narration (after the day
-	// has advanced, so e.CurrentDay reflects the new day).
-	temporalLines := applyZoneTemporalPostRollover(e)
-
-	// §4.3: starvation triggers forced extraction. With no CON tracking
-	// in this layer, the briefing-time check is the practical equivalent
-	// of "CON reaches 0" — a starvation morning means the player can't
-	// reasonably press on. Apply the §10.2 coin tax and flip status.
-	if supplyDepletion(e.Supplies) == SupplyStarvation && e.Status == ExpeditionStatusActive {
-		_, _, _ = forcedExtractExpedition(e.ID, "starvation")
-		e.Status = ExpeditionStatusAbandoned
-		line := flavor.Pick(flavor.ExtractionForced)
-		_ = appendExpeditionLog(e.ID, e.CurrentDay, "narrative",
-			"forced extraction: starvation", line)
-	}
-
-	// E5b: if a temporal event (or starvation above) forced extraction,
-	// apply the §10.2 coin tax. The temporal layer flips the row to
-	// 'abandoned'; the cycle holds the euro handle to do the debit.
-	if e.Status == ExpeditionStatusAbandoned && p.euro != nil {
-		tax := int(float64(e.CoinsEarned) * forcedExtractCoinTaxFrac)
-		if tax > 0 {
-			p.euro.Debit(id.UserID(e.UserID), float64(tax),
-				"forced extraction tax")
-		}
-	}
-
-	// E6b: sample today's threat into RegionState["max_threat_seen"] before
-	// any milestone check reads it; then award daily milestones reached by
-	// the new day count (First Night day 2, Week One day 8, Two Weeks day 15).
-	_ = recordMaxThreat(e)
-	milestoneLines := p.checkDailyMilestones(e)
 
 	line := pickMorningBriefing(e.CurrentDay)
 	body := renderMorningBriefing(e, line, burn)
 	if restSummary != "" {
 		body += "\n💤 _" + restSummary + "_\n"
 	}
-	for _, tl := range temporalLines {
+	for _, tl := range roll.TemporalLines {
 		body += "\n🌀 " + tl + "\n"
 	}
-	for _, ml := range milestoneLines {
+	for _, ml := range roll.MilestoneLines {
 		body += "\n" + ml
 	}
 
@@ -335,6 +403,80 @@ func (p *AdventurePlugin) deliverBriefing(e *Expedition, now time.Time) error {
 	return nil
 }
 
+// deliverBriefingEventAnchored — D2-b 06:00 UTC ticker for event-anchored
+// expeditions. The autopilot's night-camp pitch owns day++/burn/threat-
+// drift; the ticker just re-engages the player. If the autopilot has
+// stalled past nightSafetyNet we force-fire processNightCamp ourselves so
+// the expedition doesn't sit frozen.
+//
+// priorBriefing is the last_briefing_at value as of entry into deliverBriefing
+// (before the CAS clobbered it). nil means day-1 or genuinely never rolled.
+func (p *AdventurePlugin) deliverBriefingEventAnchored(e *Expedition, priorBriefing *time.Time) error {
+	now := time.Now().UTC()
+	var since time.Duration
+	if priorBriefing != nil {
+		since = now.Sub(*priorBriefing)
+	} else {
+		since = now.Sub(e.StartDate)
+	}
+	forced := since > nightSafetyNet
+
+	var (
+		burn          float32
+		temporalLines []string
+		mileLines     []string
+	)
+	if forced {
+		roll, err := p.processNightCamp(e)
+		if err != nil {
+			return err
+		}
+		burn = roll.Burn
+		temporalLines = roll.TemporalLines
+		mileLines = roll.MilestoneLines
+	}
+
+	line := pickMorningBriefing(e.CurrentDay)
+	body := renderMorningBriefing(e, line, burn)
+	if forced {
+		body += "\n_The autopilot stalled overnight; the day rolled over without rest._\n"
+	}
+	for _, tl := range temporalLines {
+		body += "\n🌀 " + tl + "\n"
+	}
+	for _, ml := range mileLines {
+		body += "\n" + ml
+	}
+
+	if uid := id.UserID(e.UserID); uid != "" {
+		if pet, perr := loadPetState(uid); perr == nil {
+			if petEvent := petMorningEvent(pet); petEvent != "" {
+				if char, cerr := loadAdvCharacter(uid); cerr == nil {
+					char.PetMorningDefense = true
+					if serr := saveAdvCharacter(char); serr != nil {
+						slog.Warn("expedition: save pet morning defense", "user", uid, "err", serr)
+					}
+				}
+				body = fmt.Sprintf("🐾 *%s*\n\n%s", petEvent, body)
+			}
+		}
+		if err := p.SendDM(uid, body); err != nil {
+			slog.Warn("expedition: send briefing DM", "user", uid, "err", err)
+		}
+		if forced && e.Status == ExpeditionStatusAbandoned {
+			p.maybeRollPetArrivalOnEmerge(uid)
+		}
+	}
+	summary := "morning re-engagement"
+	if forced {
+		summary = fmt.Sprintf("safety-net rollover — %.1f SU consumed overnight", burn)
+	}
+	if err := appendExpeditionLog(e.ID, e.CurrentDay, "briefing", summary, line); err != nil {
+		return err
+	}
+	return nil
+}
+
 // deliverRecap posts the evening recap DM, appends a log entry, and stamps
 // last_recap_at. No supply burn here — that's the briefing's job.
 // Idempotency: same pattern as deliverBriefing — claim last_recap_at first.

internal/plugin/dnd_expedition_cycle_test.go

@@ -14,6 +14,20 @@ import (
 // synthetic "now" and verify state transitions. Ticker scheduling is a
 // thin wrapper over those.
 
+// rewindToLegacyAnchor backdates an expedition's start_date to before
+// eventAnchoredCutoff so deliverBriefing exercises the legacy UTC-anchored
+// mutator path. Tests of the D2-b event-anchored path should NOT call this.
+func rewindToLegacyAnchor(t *testing.T, exp *Expedition) {
+	t.Helper()
+	before := eventAnchoredCutoff.Add(-24 * time.Hour)
+	if _, err := db.Get().Exec(
+		`UPDATE dnd_expedition SET start_date = ? WHERE expedition_id = ?`,
+		before, exp.ID); err != nil {
+		t.Fatal(err)
+	}
+	exp.StartDate = before
+}
+
 func TestPickMorningBriefing_DayBands(t *testing.T) {
 	cases := []struct {
 		day  int
@@ -57,6 +71,7 @@ func TestDeliverBriefing_AdvancesDayAndBurnsSupplies(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	rewindToLegacyAnchor(t, exp)
 	p := &AdventurePlugin{}
 	now := time.Now().UTC()
 	if err := p.deliverBriefing(exp, now); err != nil {
@@ -87,6 +102,76 @@ func TestDeliverBriefing_AdvancesDayAndBurnsSupplies(t *testing.T) {
 	}
 }
 
+// useEventAnchored fences the eventAnchoredCutoff to before the given
+// expedition's start_date so the D2-b path is taken. Test-scoped via t.Cleanup.
+func useEventAnchored(t *testing.T, exp *Expedition) {
+	t.Helper()
+	saved := eventAnchoredCutoff
+	eventAnchoredCutoff = exp.StartDate.Add(-time.Minute)
+	t.Cleanup(func() { eventAnchoredCutoff = saved })
+}
+
+func TestDeliverBriefing_EventAnchoredSkipsMutators(t *testing.T) {
+	setupZoneRunTestDB(t)
+	uid := id.UserID("@exp-evt-skip:example")
+	defer cleanupExpeditions(uid)
+
+	exp, err := startExpedition(uid, ZoneGoblinWarrens, "",
+		ExpeditionSupplies{Current: 10, Max: 10, DailyBurn: 1, HarshMod: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+	useEventAnchored(t, exp)
+
+	// last_briefing_at is NULL and start_date is "now-ish", so the safety
+	// net should NOT fire — sub-28h since start.
+	p := &AdventurePlugin{}
+	if err := p.deliverBriefing(exp, time.Now().UTC()); err != nil {
+		t.Fatal(err)
+	}
+	got, _ := getExpedition(exp.ID)
+	if got.CurrentDay != 1 {
+		t.Errorf("day = %d, want 1 (event-anchored briefing should not advance day)", got.CurrentDay)
+	}
+	if got.Supplies.Current != 10 {
+		t.Errorf("supplies = %v, want 10 (event-anchored briefing should not burn)", got.Supplies.Current)
+	}
+}
+
+func TestDeliverBriefing_EventAnchoredSafetyNetForces(t *testing.T) {
+	setupZoneRunTestDB(t)
+	uid := id.UserID("@exp-evt-safety:example")
+	defer cleanupExpeditions(uid)
+
+	exp, err := startExpedition(uid, ZoneGoblinWarrens, "",
+		ExpeditionSupplies{Current: 10, Max: 10, DailyBurn: 1, HarshMod: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+	useEventAnchored(t, exp)
+
+	// Backdate start_date so > nightSafetyNet has elapsed with no rollover.
+	before := time.Now().UTC().Add(-(nightSafetyNet + time.Hour))
+	if _, err := db.Get().Exec(
+		`UPDATE dnd_expedition SET start_date = ? WHERE expedition_id = ?`,
+		before, exp.ID); err != nil {
+		t.Fatal(err)
+	}
+	exp.StartDate = before
+
+	p := &AdventurePlugin{}
+	if err := p.deliverBriefing(exp, time.Now().UTC()); err != nil {
+		t.Fatal(err)
+	}
+	got, _ := getExpedition(exp.ID)
+	if got.CurrentDay != 2 {
+		t.Errorf("day = %d, want 2 (safety net should force rollover)", got.CurrentDay)
+	}
+	if got.Supplies.Current >= 10 {
+		t.Errorf("supplies = %v, want < 10 (safety net should burn)", got.Supplies.Current)
+	}
+}
+
 func TestDeliverBriefing_HarshConditionsBurnFaster(t *testing.T) {
 	setupZoneRunTestDB(t)
 	uid := id.UserID("@exp-cycle-harsh:example")
@@ -97,6 +182,7 @@ func TestDeliverBriefing_HarshConditionsBurnFaster(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	rewindToLegacyAnchor(t, exp)
 	// Force harsh conditions via threat clock above 60.
 	if err := applyThreatDelta(exp.ID, 70, "test"); err != nil {
 		t.Fatal(err)

internal/plugin/dnd_expedition_temporal_test.go

@@ -701,6 +701,7 @@ func TestAbyss_DailyInstabilityIncrements(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	rewindToLegacyAnchor(t, exp)
 	p := &AdventurePlugin{}
 	// Three briefings → instability should hit 15.
 	for i := 0; i < 3; i++ {
@@ -732,6 +733,7 @@ func TestAbyss_UnravelingDoublesBurn(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	rewindToLegacyAnchor(t, exp)
 	// Set instability to 85 (unravel band).
 	if _, err := db.Get().Exec(
 		`UPDATE dnd_expedition SET temporal_stack = 85 WHERE expedition_id = ?`,
@@ -760,6 +762,7 @@ func TestAbyss_CollapseFailsExpedition(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	rewindToLegacyAnchor(t, exp)
 	// Set instability to 95 — next daily +5 lands on 100 (collapse).
 	if _, err := db.Get().Exec(
 		`UPDATE dnd_expedition SET temporal_stack = 95 WHERE expedition_id = ?`,

internal/plugin/dnd_expedition_threat_test.go

@@ -150,6 +150,7 @@ func TestDeliverBriefing_AppliesThreatDrift(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	rewindToLegacyAnchor(t, exp)
 	p := &AdventurePlugin{}
 	if err := p.deliverBriefing(exp, time.Now().UTC()); err != nil {
 		t.Fatal(err)

internal/plugin/expedition_autocamp.go

@@ -36,6 +36,15 @@ const (
 	// this fraction of max. Set above autopilotLowHPPct (0.30) so the
 	// scheduler camps *before* the walk-preflight gives up.
 	autoCampHPPct = 0.55
+
+	// nightCampWindow — D2-b. Event-anchored expeditions roll the day on
+	// autopilot night-camp pitch. After this many hours since the last
+	// rollover, the next eligible camp is treated as the night camp
+	// (Night=true) and triggers processNightCamp. 16h gives the player
+	// most of an active day before the engine starts wanting to bed
+	// down; a healthy party with no HP pressure still camps at the end
+	// of the day rather than walking forever.
+	nightCampWindow = 16 * time.Hour
 )
 
 // autoCampInputs is the minimal snapshot decideAutopilotCamp needs.
@@ -49,13 +58,21 @@ type autoCampInputs struct {
 	BaseAlready   bool
 	HPCur, HPMax  int
 	Supplies      ExpeditionSupplies
+	// D2-b: event-anchored rollover inputs.
+	Now            time.Time
+	EventAnchored  bool
+	LastBriefingAt *time.Time
+	StartDate      time.Time
 }
 
 // autoCampDecision — what to pitch and why. Reason is a short log-line
-// fragment ("region boss cleared", "HP low").
+// fragment ("region boss cleared", "HP low"). Night=true means the
+// caller should run processNightCamp as part of the pitch so the day++/
+// supply burn / threat drift happen alongside the rest.
 type autoCampDecision struct {
 	Kind   string
 	Reason string
+	Night  bool
 }
 
 // decideAutopilotCamp returns the camp to pitch (or ok=false). Pure;
@@ -79,21 +96,38 @@ func decideAutopilotCamp(in autoCampInputs) (autoCampDecision, bool) {
 		}
 	}
 
+	// D2-b: night-camp window — for event-anchored expeditions, the
+	// autopilot pitches the day's rollover camp when enough real time
+	// has elapsed since the last rollover. A flag, not a separate
+	// branch, so each pitch below can become a night camp.
+	night := false
+	if in.EventAnchored {
+		var since time.Duration
+		if in.LastBriefingAt != nil {
+			since = in.Now.Sub(*in.LastBriefingAt)
+		} else {
+			since = in.Now.Sub(in.StartDate)
+		}
+		night = since >= nightCampWindow
+	}
+
 	// Heuristic — region base-camp waypoint. Eager: pitch once per
 	// eligible region after its boss is down. BaseAlready stops the
 	// next tick from re-pitching the same waypoint.
 	if in.Multi && in.RegionCleared && in.BaseSite && !in.BaseAlready && cleared {
 		if in.Supplies.Current >= campSupplyCost[CampTypeBase] {
-			return autoCampDecision{Kind: CampTypeBase, Reason: "region boss cleared — pitching base camp waypoint"}, true
+			return autoCampDecision{
+				Kind: CampTypeBase, Night: night,
+				Reason: "region boss cleared — pitching base camp waypoint",
+			}, true
 		}
 	}
 
-	// Heuristic — HP-low rest. Standard if cleared, rough otherwise.
+	// Heuristic — HP-low rest OR end-of-day night camp. Standard if
-	// LowSU as a *trigger* would just dig the hole deeper (camps burn
+	// cleared, rough otherwise. LowSU as a *trigger* would just dig
-	// SU); the walk's preflight already pauses on low-SU so the
+	// the hole deeper; the walk's preflight pauses on low-SU instead.
-	// player can extract or buy more time.
 	lowHP := in.HPMax > 0 && float64(in.HPCur) <= float64(in.HPMax)*autoCampHPPct
-	if !lowHP {
+	if !lowHP && !night {
 		return autoCampDecision{}, false
 	}
 	kind := CampTypeRough
@@ -102,14 +136,20 @@ func decideAutopilotCamp(in autoCampInputs) (autoCampDecision, bool) {
 	}
 	cost := campSupplyCost[kind]
 	if in.Supplies.Current < cost {
-		// Try the cheaper rough tier if standard doesn't fit.
 		if kind == CampTypeStandard && in.Supplies.Current >= campSupplyCost[CampTypeRough] {
 			kind = CampTypeRough
 		} else {
 			return autoCampDecision{}, false
 		}
 	}
-	return autoCampDecision{Kind: kind, Reason: "HP low — pitching rest camp"}, true
+	reason := "HP low — pitching rest camp"
+	switch {
+	case night && lowHP:
+		reason = "HP low + end of day — pitching night camp"
+	case night:
+		reason = "end of day — pitching night camp"
+	}
+	return autoCampDecision{Kind: kind, Reason: reason, Night: night}, true
 }
 
 // maybeAutoCamp gathers DB state, calls decideAutopilotCamp, and pitches
@@ -139,15 +179,19 @@ func (p *AdventurePlugin) maybeAutoCamp(exp *Expedition) string {
 
 	hpCur, hpMax := dndHPSnapshot(uid)
 	in := autoCampInputs{
-		Camp:          exp.Camp,
+		Camp:           exp.Camp,
-		Run:           run,
+		Run:            run,
-		Multi:         multi,
+		Multi:          multi,
-		RegionCleared: regionCleared,
+		RegionCleared:  regionCleared,
-		BaseSite:      baseSite,
+		BaseSite:       baseSite,
-		BaseAlready:   baseAlready,
+		BaseAlready:    baseAlready,
-		HPCur:         hpCur,
+		HPCur:          hpCur,
-		HPMax:         hpMax,
+		HPMax:          hpMax,
-		Supplies:      exp.Supplies,
+		Supplies:       exp.Supplies,
+		Now:            time.Now().UTC(),
+		EventAnchored:  isEventAnchored(exp),
+		LastBriefingAt: exp.LastBriefingAt,
+		StartDate:      exp.StartDate,
 	}
 	d, ok := decideAutopilotCamp(in)
 	if !ok {
@@ -164,8 +208,37 @@ func (p *AdventurePlugin) maybeAutoCamp(exp *Expedition) string {
 // pitchAutopilotCamp performs the same state mutations as the player
 // !camp path (supply debit, camp row, applyCampRest, log entry, base-
 // camp waypoint persist) without DMing — the autorun ticker bundles
-// the returned block into the single auto-walk DM.
+// the returned block into the single auto-walk DM. When d.Night is true
+// (D2-b event-anchored rollover), the day++/burn/threat-drift fire here
+// too: nightRolloverBurn before the camp cost (so the burn lands on
+// pre-pitch supplies, matching the legacy morning-burn ordering), then
+// applyCampRest, then nightRolloverDrift.
 func (p *AdventurePlugin) pitchAutopilotCamp(exp *Expedition, d autoCampDecision) (string, error) {
+	var (
+		nightBurn  float32
+		nightTemp  []string
+		nightMile  []string
+		nightDid   bool
+		nightForce bool
+	)
+	if d.Night {
+		burn, err := p.nightRolloverBurn(exp)
+		if err != nil {
+			return "", err
+		}
+		nightBurn = burn
+		nightDid = true
+		if exp.Status != ExpeditionStatusActive {
+			// Starvation during burn is rare (burn alone doesn't trigger
+			// starvation — that needs supplies <= 0 *after* burn), but
+			// guard anyway so we don't pitch a camp on an abandoned exp.
+			drift := p.nightRolloverDrift(exp, time.Now().UTC())
+			nightTemp = drift.TemporalLines
+			nightMile = drift.MilestoneLines
+			nightForce = true
+			return renderAutoCampBlock(exp, d, 0, "", "", nightBurn, nightTemp, nightMile, nightDid, nightForce), nil
+		}
+	}
 	cost := campSupplyCost[d.Kind]
 	if exp.Supplies.Current < cost {
 		return "", fmt.Errorf("insufficient supplies (have %.1f, need %.1f)", exp.Supplies.Current, cost)
@@ -211,13 +284,32 @@ func (p *AdventurePlugin) pitchAutopilotCamp(exp *Expedition, d autoCampDecision
 		}
 	}
 
-	return renderAutoCampBlock(exp, d, cost, line, restSummary), nil
+	if d.Night {
+		drift := p.nightRolloverDrift(exp, time.Now().UTC())
+		nightTemp = drift.TemporalLines
+		nightMile = drift.MilestoneLines
+	}
+
+	return renderAutoCampBlock(exp, d, cost, line, restSummary,
+		nightBurn, nightTemp, nightMile, nightDid, nightForce), nil
 }
 
 // renderAutoCampBlock formats the autopilot-camp section appended to
 // the auto-walk DM. Kept short — the autorun DM already opens with the
-// walk narration.
+// walk narration. nightBurn/nightTemp/nightMile carry the D2-b rollover
-func renderAutoCampBlock(exp *Expedition, d autoCampDecision, cost float32, flavorLine, restSummary string) string {
+// side effects when the pitch was a night camp.
+func renderAutoCampBlock(exp *Expedition, d autoCampDecision, cost float32, flavorLine, restSummary string,
+	nightBurn float32, nightTemp []string, nightMile []string, nightDid bool, nightForce bool) string {
+	if nightForce {
+		out := fmt.Sprintf("\n\n🌙 **Day %d.** _Supplies burned (−%.1f SU); the rollover fired but the camp couldn't pitch._\n", exp.CurrentDay, nightBurn)
+		for _, tl := range nightTemp {
+			out += "\n🌀 " + tl + "\n"
+		}
+		for _, ml := range nightMile {
+			out += "\n" + ml
+		}
+		return out
+	}
 	out := fmt.Sprintf("\n\n⛺ **Autopilot camp — %s.** _%s_\n", d.Kind, d.Reason)
 	out += fmt.Sprintf("Supplies: %.1f / %.1f SU (−%.1f).\n",
 		exp.Supplies.Current, exp.Supplies.Max, cost)
@@ -230,6 +322,15 @@ func renderAutoCampBlock(exp *Expedition, d autoCampDecision, cost float32, flav
 	if d.Kind == CampTypeBase {
 		out += "\n_Base camp — **waypoint persisted**._"
 	}
+	if nightDid {
+		out += fmt.Sprintf("\n\n🌙 **Day %d.** _Overnight burn: %.1f SU._\n", exp.CurrentDay, nightBurn)
+		for _, tl := range nightTemp {
+			out += "\n🌀 " + tl + "\n"
+		}
+		for _, ml := range nightMile {
+			out += "\n" + ml
+		}
+	}
 	return out
 }
 

internal/plugin/expedition_autocamp_test.go

@@ -223,6 +223,101 @@ func TestBreakAutoCampIfDue_RespectsDwellWindow(t *testing.T) {
 	}
 }
 
+func TestDecideAutopilotCamp_NightTriggerOnEventAnchored(t *testing.T) {
+	now := time.Now().UTC()
+	stale := now.Add(-(nightCampWindow + time.Hour))
+	in := autoCampInputs{
+		Run:            &DungeonRun{CurrentRoom: 1, RoomsCleared: []int{0, 1}},
+		HPCur:          20, HPMax: 20, // healthy — only the night window should pitch
+		Supplies:       ExpeditionSupplies{Current: 5, Max: 5, DailyBurn: 1},
+		Now:            now,
+		EventAnchored:  true,
+		LastBriefingAt: &stale,
+	}
+	d, ok := decideAutopilotCamp(in)
+	if !ok {
+		t.Fatal("expected night camp pitch")
+	}
+	if !d.Night {
+		t.Errorf("Night = false, want true (end of day)")
+	}
+	if d.Kind != CampTypeStandard {
+		t.Errorf("Kind = %s, want standard (cleared room)", d.Kind)
+	}
+}
+
+func TestDecideAutopilotCamp_NightSkippedOnLegacy(t *testing.T) {
+	now := time.Now().UTC()
+	stale := now.Add(-24 * time.Hour)
+	in := autoCampInputs{
+		Run:            &DungeonRun{CurrentRoom: 1, RoomsCleared: []int{0, 1}},
+		HPCur:          20, HPMax: 20,
+		Supplies:       ExpeditionSupplies{Current: 5, Max: 5, DailyBurn: 1},
+		Now:            now,
+		EventAnchored:  false, // legacy — only HP-low triggers
+		LastBriefingAt: &stale,
+	}
+	if _, ok := decideAutopilotCamp(in); ok {
+		t.Error("legacy expedition should not pitch a night camp on time alone")
+	}
+}
+
+func TestDecideAutopilotCamp_NightFlagSetEvenOnHPLow(t *testing.T) {
+	now := time.Now().UTC()
+	stale := now.Add(-(nightCampWindow + time.Hour))
+	in := autoCampInputs{
+		Run:            &DungeonRun{CurrentRoom: 1, RoomsCleared: []int{0, 1}},
+		HPCur:          5, HPMax: 20, // also low
+		Supplies:       ExpeditionSupplies{Current: 5, Max: 5, DailyBurn: 1},
+		Now:            now,
+		EventAnchored:  true,
+		LastBriefingAt: &stale,
+	}
+	d, ok := decideAutopilotCamp(in)
+	if !ok || !d.Night {
+		t.Errorf("expected Night pitch even when HP also low, got %+v ok=%v", d, ok)
+	}
+}
+
+func TestPitchAutopilotCamp_NightRunsProcessNightCamp(t *testing.T) {
+	setupZoneRunTestDB(t)
+	uid := id.UserID("@autocamp-night:example")
+	campTestCharacter(t, uid, 1)
+	defer cleanupExpeditions(uid)
+
+	exp, err := startExpedition(uid, ZoneGoblinWarrens, "",
+		ExpeditionSupplies{Current: 5, Max: 5, DailyBurn: 1, HarshMod: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Force event-anchored for this test.
+	saved := eventAnchoredCutoff
+	eventAnchoredCutoff = exp.StartDate.Add(-time.Minute)
+	defer func() { eventAnchoredCutoff = saved }()
+
+	startDay := exp.CurrentDay
+	startSU := exp.Supplies.Current
+	p := &AdventurePlugin{}
+	_, err = p.pitchAutopilotCamp(exp, autoCampDecision{
+		Kind: CampTypeStandard, Reason: "night-camp test", Night: true,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, _ := getActiveExpedition(uid)
+	if got.CurrentDay != startDay+1 {
+		t.Errorf("day = %d, want %d (night camp advances day)", got.CurrentDay, startDay+1)
+	}
+	// Night burn (0.5 SU) + camp cost (1.0 SU) = 1.5 SU; 5 - 1.5 = 3.5.
+	wantSU := startSU - 0.5 - campSupplyCost[CampTypeStandard]
+	if got.Supplies.Current != wantSU {
+		t.Errorf("supplies = %v, want %v (night burn + camp cost)", got.Supplies.Current, wantSU)
+	}
+	if got.LastBriefingAt == nil {
+		t.Error("LastBriefingAt should be stamped by night rollover")
+	}
+}
+
 func TestBreakAutoCampIfDue_LeavesPlayerCampAlone(t *testing.T) {
 	setupZoneRunTestDB(t)
 	uid := id.UserID("@autocamp-playercamp:example")

internal/plugin/holdem_tip_scenarios_test.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/chehsunliu/poker"
 )
@@ -30,6 +31,11 @@ func loadSolverFixture() {
 
 func TestMain(m *testing.M) {
 	loadSolverFixture()
+	// D2-b: shove eventAnchoredCutoff far into the future so existing tests
+	// keep exercising the legacy UTC-anchored briefing mutator path by
+	// default. New event-anchored tests opt in by overriding the cutoff
+	// (see useEventAnchored helpers).
+	eventAnchoredCutoff = time.Date(9999, 1, 1, 0, 0, 0, 0, time.UTC)
 	os.Exit(m.Run())
 }