Relocate Immaculate Heart of Mary off Aug 22 to Easter+69

Fixed Aug 22 collided outright with the Assumption's own octave-closing
day (both this project's blended calendar tracks are kept deliberately,
so one shouldn't permanently suppress the other). Moved IHM to the
Saturday after the Feast of the Sacred Heart -- its real diocesan date
from 1914 until Pius XII's 1944 fixed-date decree, and also the date the
1969 reform returned to.

Required real new mechanism, not just a data move: a new bespoke
calendar/index.ts override (applyImmaculateHeart, following the existing
applyMarianSaturday/applyChristTheKing precedent), a move from the
sanctoral saints store to the temporal-feasts store (different propers
lookup entirely), and a real bug fix in matins.ts's nocturnReadingIds,
which only ever picked up a *sanctoral* winner's own reading file.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VZSAgRi4QE4XRTqVto93zA

src/calendar/index.ts

@@ -105,6 +105,7 @@ export function resolveDay(isoDate: string): LiturgicalDay {
   winner = applyMarianSaturday(isoDate, weekday, temporalCategory, winner, commemorations);
   winner = applyChristTheKing(isoDate, winner, commemorations);
   winner = applyChristmasOctaveSunday(isoDate, weekday, winner, commemorations);
+  winner = applyImmaculateHeart(isoDate, winner, commemorations);
   applyEpiphany6Commemoration(isoDate, commemorations);
 
   return { date: isoDate, weekday, season, temporalCategory, winner, commemorations };
@@ -244,6 +245,54 @@ function applyChristmasOctaveSunday(
   return winner;
 }
 
+/**
+ * User decision, 2026-08-22: relocated off the fixed Aug 22 date (which
+ * collided outright with the Assumption's own octave-closing day —
+ * Pius XII's 1944 decree fixed it there, but this project keeps the
+ * older Tridentine "Octave Day of the Assumption" too) to the *other*
+ * well-documented historical assignment: the Saturday after the Feast
+ * of the Sacred Heart. Real history (not a guess): this was the
+ * feast's actual diocesan date from 1914 until the 1944 fixed-date
+ * decree, and is also the date Paul VI's 1969 reform returned to — so
+ * it has continuity on both sides of the Aug-22 interlude, unlike
+ * inventing a "Saturday after the octave of Sacred Heart" pattern (no
+ * such rule was ever real; Sacred Heart itself doesn't even have an
+ * octave modeled in this codebase). Sacred Heart is Easter+68 (always
+ * a Friday, see data/calendar/easter-offsets.yml's own derivation
+ * comment) — this is the very next day, Easter+69.
+ *
+ * Runs last, after applyMarianSaturday, deliberately: Easter+69 is
+ * always a Saturday, so absent this override the day would otherwise
+ * just fall to the generic "Our Lady's Saturday" default — a specific
+ * named Marian feast should always supersede that generic filler, not
+ * lose to whichever ran first. Any temporal winner reaching here
+ * (marian-saturday or a plain post-Pentecost Sunday-of-the-week id)
+ * has no real standing of its own and is simply superseded, same as
+ * applyChristTheKing's unconditional-when-temporal branch. Rank
+ * compared via compareFeastClass, same as every other override in this
+ * file — a duplex-2-classis feast displaces anything weaker, but a
+ * higher-ranked sanctoral saint who happens to land on the same
+ * Saturday keeps the day and Immaculate Heart is commemorated instead.
+ */
+function applyImmaculateHeart(isoDate: string, winner: DayWinner, commemorations: Commemoration[]): DayWinner {
+  const year = Number(isoDate.slice(0, 4));
+  const targetDate = addDays(toIsoDate(easterSunday(year)), 69);
+  if (isoDate !== targetDate) {
+    return winner;
+  }
+  const IMMACULATE_HEART: DayWinner = { kind: 'temporal', id: 'immaculate-heart-of-mary' };
+  if (winner.kind === 'temporal') {
+    commemorations.push({ kind: 'temporal', id: winner.id });
+    return IMMACULATE_HEART;
+  }
+  if (compareFeastClass(winner.rank, 'duplex-2-classis') >= 0) {
+    commemorations.push({ kind: 'temporal', id: 'immaculate-heart-of-mary' });
+    return winner;
+  }
+  commemorations.push({ kind: 'sanctoral', id: winner.id, name: winner.name, rank: winner.rank });
+  return IMMACULATE_HEART;
+}
+
 /**
  * Layered on top of everything above, same spirit as applyOctaves: never
  * changes decideOccurrence's own rules, just relabels the result on a free

src/data/calendar/saints/immaculate-heart-of-mary.yml

@@ -1,13 +0,0 @@
-# Read directly from the reference engine: untagged/default [Rank]
-# block of `web/www/horas/Latin/Sancti/08-22.txt` -- "Immaculati Cordis
-# Beatæ Mariæ Virginis;;Duplex II classis;;5.1;;ex C11". Own real
-# [Oratio] and own [Ant 1]. Own Nocturn 2-3 content (Nocturn 3 is St.
-# Robert Bellarmine's own homily on the seven words of Christ on the
-# Cross, not a cross-reference). Instituted 1942 by Pius XII (see the
-# feast's own Lectio6, quoted in nocturn-readings, drawn from
-# ecclesiastical documents).
-id: immaculate-heart-of-mary
-name: "The Immaculate Heart of the Blessed Virgin Mary"
-rank: duplex-2-classis
-common: common-of-the-bvm
-propers: "immaculate-heart-of-mary"

src/data/calendar/sanctoral-calendar.yml

@@ -269,7 +269,6 @@ days:
   "08-19": [st-john-eudes]
   "08-20": [st-bernard]
   "08-21": [st-jane-frances-de-chantal]
-  "08-22": [immaculate-heart-of-mary]
   "08-23": [vigil-of-st-bartholomew]
   "08-24": [st-bartholomew]
   "08-25": [st-louis]

src/data/calendar/temporal-feasts/immaculate-heart-of-mary.yml

@@ -0,0 +1,14 @@
+# Relocated off the fixed Aug 22 date (2026-08-22 user decision) -- that
+# date collided outright with the Assumption's own octave-closing day,
+# which this project also deliberately keeps (see saints/assumption.yml).
+# Moved to the Saturday after the Feast of the Sacred Heart (Easter+69,
+# see calendar/index.ts's applyImmaculateHeart) -- the feast's own real
+# diocesan date from 1914 until Pius XII's 1944 fixed-date decree, and
+# also the date Paul VI's 1969 reform returned to, so it has continuity
+# on both sides of the Aug-22 interlude. Rank/name still sourced from
+# `web/www/horas/Latin/Sancti/08-22.txt`'s own [Rank] block, same as
+# before the move -- only the date assignment changed, not the office's
+# own content.
+id: immaculate-heart-of-mary
+name: "The Immaculate Heart of the Blessed Virgin Mary"
+rank: duplex-2-classis

src/data/propers/temporal/immaculate-heart-of-mary-benedictus-antiphon.yml

@@ -1,7 +1,11 @@
 # Read directly from web/www/horas/Latin/Sancti/08-22.txt's own
 # [Ant 1] and its English counterpart -- a real, proper antiphon of
-# this feast, not a Common substitution.
-id: immaculate-heart-of-mary-antiphon
+# this feast, not a Common substitution. Duplicated as both Benedictus
+# and Magnificat antiphon (see the -magnificat- sibling file): the
+# source only carries this single [Ant 1], and the temporal propers
+# store keys the two separately, unlike the sanctoral store's single
+# shared `${propers}-antiphon`.
+id: immaculate-heart-of-mary-benedictus-antiphon
 text:
   la: "Exsultávit cor meum * in Dómino, et exaltátum est cornu meum in Deo meo, quia lætáta sum in salutári tuo."
   en: "My heart hath rejoiced in the Lord, * and my horn is exalted in my God: because I have joyed in thy salvation."

src/data/propers/temporal/immaculate-heart-of-mary-magnificat-antiphon.yml

@@ -0,0 +1,14 @@
+# Read directly from web/www/horas/Latin/Sancti/08-22.txt's own
+# [Ant 1] and its English counterpart -- a real, proper antiphon of
+# this feast, not a Common substitution. Duplicated as both Benedictus
+# and Magnificat antiphon (see the -benedictus- sibling file): the
+# source only carries this single [Ant 1], and the temporal propers
+# store keys the two separately, unlike the sanctoral store's single
+# shared `${propers}-antiphon`.
+id: immaculate-heart-of-mary-magnificat-antiphon
+text:
+  la: "Exsultávit cor meum * in Dómino, et exaltátum est cornu meum in Deo meo, quia lætáta sum in salutári tuo."
+  en: "My heart hath rejoiced in the Lord, * and my horn is exalted in my God: because I have joyed in thy salvation."
+status:
+  la: verified
+  en: verified

src/hours/matins.ts

@@ -300,7 +300,13 @@ function ferialPsalmodyThreeNocturns(day: LiturgicalDay): [ResolvedPart[], Resol
  * user's own "be generous, not winner-takes-all" instruction (2026-08). */
 function nocturnReadingIds(day: LiturgicalDay, temporalId: string): string[] {
   const ids = new Set<string>();
-  if (day.winner.kind === 'sanctoral') ids.add(day.winner.id);
+  // Not gated to `kind === 'sanctoral'` -- a named temporal override (e.g.
+  // Immaculate Heart of Mary, calendar/index.ts's applyImmaculateHeart)
+  // has its own authored nocturn-readings file keyed by its own id too,
+  // distinct from the plain governing-Sunday `temporalId` added below.
+  // Harmless to include unconditionally: on an ordinary day `day.winner.id`
+  // already equals `temporalId`, so the Set just dedupes.
+  ids.add(day.winner.id);
   for (const c of day.commemorations) {
     if (c.kind === 'sanctoral') ids.add(c.id);
   }

src/hours/resolve-common.ts

@@ -35,7 +35,12 @@ export function resolveCommon(id: string): ResolvedText {
 // override-eligible — see hours/lauds.ts's getPsalmodyOverrideFor, which
 // shares this set (imported from here, not duplicated) since it's the
 // same "does this temporal identity carry its own real office" question.
-export const ALWAYS_OVERRIDE_TEMPORAL_IDS = new Set(['marian-saturday', 'christ-the-king', 'christmas-octave-sunday']);
+export const ALWAYS_OVERRIDE_TEMPORAL_IDS = new Set([
+  'marian-saturday',
+  'christ-the-king',
+  'christmas-octave-sunday',
+  'immaculate-heart-of-mary',
+]);
 
 /**
  * Which identity's own propers actually supply the office's content