Show a transferred saint's status in the day label

getDayLabel now surfaces the transfer signal added in the previous
commit: a transferred-in winner gets "(Rank, transferred)" instead of
just "(Rank)"; a transferred-in commemoration gets "(transferred)"
appended to its bare name; and the date a saint transferred away from
gets a trailing "St. X (transferred away)" note so a reader isn't left
wondering why an expected saint is missing that day. Deliberately worded
differently on the two sides (plain "transferred" reads as "arrived via
transfer" next to a rank parenthetical; "transferred away" spells out the
direction on the origin date, where there's no rank alongside it to
anchor that reading) and deliberately omits a landing date on the away
note, per direct instruction, since a real landing can chain further than
the single adjacent day resolveDay actually checks (an unmodeled case,
e.g. a transfer running into Holy Week).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013g7AsSvMD9oazR17f3BxLz

src/calendar/day-label.ts

@@ -443,11 +443,18 @@ function collectCommemorations(
   for (const c of day.commemorations) {
     if (c.kind === 'sanctoral') {
       const name = biName(c.name, c.nameLa);
-      sanctoral.push(
-        c.vespersNote
-          ? bi(`${name.en} (${CROSS_DAY_VESPERS_LABELS[c.vespersNote].en})`, `${name.la} (${CROSS_DAY_VESPERS_LABELS[c.vespersNote].la})`)
-          : name,
-      );
+      if (c.vespersNote) {
+        sanctoral.push(bi(`${name.en} (${CROSS_DAY_VESPERS_LABELS[c.vespersNote].en})`, `${name.la} (${CROSS_DAY_VESPERS_LABELS[c.vespersNote].la})`));
+      } else if (c.transferredFrom) {
+        // Same "arrived via transfer, not natively due here" signal as a
+        // transferred-in *winner* gets — a reader shouldn't need to already
+        // know this saint's real date to realize a mere commemoration here
+        // is standing in for a transfer, not this date's own natural
+        // sanctoral standing.
+        sanctoral.push(bi(`${name.en} (${TRANSFERRED_LABEL.en})`, `${name.la} (${TRANSFERRED_LABEL.la})`));
+      } else {
+        sanctoral.push(name);
+      }
     } else if (c.kind === 'temporal') {
       if (c.id === temporalId) {
         temporal.push(anchorDayName(day, false) ?? temporalLabel(day));
@@ -520,6 +527,44 @@ export function getVespersStatusLabel(day: LiturgicalDay, requestedDate: string)
   return bi('Second Vespers (of today)', 'Vesperæ de hodierno');
 }
 
+/** Appended after a transferred-in winner's name/rank, before any
+ * commemorations — same shape as a rank parenthetical. Distinct wording
+ * from `TRANSFERRED_AWAY_LABEL` below on purpose: this winner's own rank
+ * parenthetical sits right next to it ("St. X (Duplex, transferred)"), so
+ * plain "transferred" already reads as "arrived via transfer" in context —
+ * but on the origin date there's no rank alongside it to anchor that
+ * reading, so the away-note spells out the direction explicitly instead of
+ * relying on that same subtlety a first-time reader wouldn't have. */
+const TRANSFERRED_LABEL = bi('transferred', 'translata');
+
+/** See `TRANSFERRED_LABEL`'s doc comment for why this is worded differently. */
+const TRANSFERRED_AWAY_LABEL = bi('transferred away', 'translata alio');
+
+/** "St. X (transferred away)" note for a date whose own native sanctoral
+ * candidate (`day.transferredAway`) couldn't be kept here — appended after
+ * everything else `getDayLabel` already found for this date's real
+ * winner/commemorations, since the departure is a footnote about a
+ * *different* saint, not part of this date's own identity. Deliberately
+ * names no landing date (see `transferredAway`'s own doc comment) — the
+ * point is just to tell a reader "not an omission, this office moved
+ * elsewhere," not to claim a specific destination that a later, unmodeled
+ * transfer chain could make wrong. */
+function transferredAwayNote(day: LiturgicalDay): Bi | undefined {
+  if (!day.transferredAway) {
+    return undefined;
+  }
+  const name = biName(day.transferredAway.candidate.name, day.transferredAway.candidate.nameLa);
+  return bi(`${name.en} (${TRANSFERRED_AWAY_LABEL.en})`, `${name.la} (${TRANSFERRED_AWAY_LABEL.la})`);
+}
+
+function withTransferNote(day: LiturgicalDay, label: Partial<Record<string, string>>): Partial<Record<string, string>> {
+  const note = transferredAwayNote(day);
+  if (!note) {
+    return label;
+  }
+  return { en: `${label.en} — ${note.en}`, la: `${label.la} — ${note.la}` };
+}
+
 /**
  * The full "day being celebrated" label: the day's own primary identity
  * (a sanctoral winner, a named temporal feast, a season's own anchor day,
@@ -547,8 +592,10 @@ export function getDayLabel(day: LiturgicalDay): Partial<Record<string, string>>
     });
     const rank = formatRank(day.winner.rank);
     const winnerName = biName(day.winner.name, day.winner.nameLa);
-    const winner = bi(`${winnerName.en} (${rank.en})`, `${winnerName.la} (${rank.la})`);
-    return joinBi([winner, ...temporal, ...sanctoral, ...octaves]);
+    const winner = day.winner.transferredFrom
+      ? bi(`${winnerName.en} (${rank.en}, ${TRANSFERRED_LABEL.en})`, `${winnerName.la} (${rank.la}, ${TRANSFERRED_LABEL.la})`)
+      : bi(`${winnerName.en} (${rank.en})`, `${winnerName.la} (${rank.la})`);
+    return withTransferNote(day, joinBi([winner, ...temporal, ...sanctoral, ...octaves]));
   }
 
   // A named temporal feast (Christmas, Pentecost, Marian Saturday, ...)
@@ -563,7 +610,7 @@ export function getDayLabel(day: LiturgicalDay): Partial<Record<string, string>>
       ? bi(`${name.en} (${formatRank(namedFeast.rank).en})`, `${name.la} (${formatRank(namedFeast.rank).la})`)
       : name;
     const { sanctoral } = collectCommemorations(day, { showOctaves: false });
-    return joinBi([primary, ...sanctoral]);
+    return withTransferNote(day, joinBi([primary, ...sanctoral]));
   }
 
   // A season's own named anchor day (Trinity Sunday, Easter, Ash
@@ -576,7 +623,7 @@ export function getDayLabel(day: LiturgicalDay): Partial<Record<string, string>>
   const anchorName = anchorDayName(day);
   if (anchorName) {
     const { sanctoral } = collectCommemorations(day, { showOctaves: false });
-    return joinBi([anchorName, ...sanctoral]);
+    return withTransferNote(day, joinBi([anchorName, ...sanctoral]));
   }
 
   // An active octave (St. Lawrence's, ...) is this day's real primary
@@ -612,12 +659,12 @@ export function getDayLabel(day: LiturgicalDay): Partial<Record<string, string>>
   if (activeOctave) {
     const { sanctoral, octaves } = collectCommemorations(day, { showOctaves: true, excludeOctaveId: activeOctave.id });
     const primary = octaveLabel(activeOctave);
-    return joinBi([primary, ...octaves, ...sanctoral]);
+    return withTransferNote(day, joinBi([primary, ...octaves, ...sanctoral]));
   }
 
   const temporalRank = TEMPORAL_CATEGORY_RANK_LABELS[day.temporalCategory];
   const label = temporalLabel(day);
   const temporal = bi(`${label.en} (${temporalRank.en})`, `${label.la} (${temporalRank.la})`);
   const { sanctoral } = collectCommemorations(day, { showOctaves: false });
-  return joinBi([temporal, ...sanctoral]);
+  return withTransferNote(day, joinBi([temporal, ...sanctoral]));
 }

src/calendar/index.ts

@@ -56,6 +56,7 @@ function applyIncomingTransfer(
   temporalCategory: TemporalCategory,
   winner: DayWinner,
   commemorations: Commemoration[],
+  fromDate: string,
 ): DayWinner {
   if (temporalCategory === 'privileged-feria-major') {
     // Deferred: a transfer landing on one of these (the concrete case is
@@ -67,6 +68,18 @@ function applyIncomingTransfer(
     // ordinary-sunday landing.
     return winner;
   }
+  // Tags the returned winner with where it transferred from, but only when
+  // the candidate actually ended up winning here — a collision loss (the
+  // candidate merely commemorated, incumbent keeps the day) isn't a landing.
+  const tagIfLanded = (result: DayWinner): DayWinner =>
+    result.kind === 'sanctoral' && result.id === candidate.id ? { ...result, transferredFrom: fromDate } : result;
+  // Same tagging, but for the candidate's own *commemoration* — it still
+  // needs marking as arrived-via-transfer even when it lost the landing
+  // day outright (a collision loss, or falling below the landing day's own
+  // threshold in decideOccurrence) rather than merely being naturally due
+  // for commemoration here.
+  const tagCommemorations = (result: Commemoration[]): Commemoration[] =>
+    result.map((c) => (c.kind === 'sanctoral' && c.id === candidate.id ? { ...c, transferredFrom: fromDate } : c));
   if (winner.kind === 'temporal') {
     // Found via real data: a transferred-in Simplex saint was blindly
     // winning outright even when it landed on a privileged Sunday (Trinity
@@ -74,15 +87,15 @@ function applyIncomingTransfer(
     // the *same* precedence rules a native occurrence would have used,
     // not just take over because nothing else was assigned here.
     const decided = decideOccurrence(temporalCategory, winner.id, candidate);
-    commemorations.push(...decided.commemorations);
+    commemorations.push(...tagCommemorations(decided.commemorations));
     // If the candidate fails here too (decided.transfer set), that's a
     // transfer chain — not modeled, same "not delivered rather than
     // guessed at" stance as the privileged-feria-major case above.
-    return decided.winner;
+    return tagIfLanded(decided.winner);
   }
   const collision = resolveCollision(candidate, winner);
-  commemorations.push(...collision.commemorations);
-  return collision.winner;
+  commemorations.push(...tagCommemorations(collision.commemorations));
+  return tagIfLanded(collision.winner);
 }
 
 /**
@@ -99,13 +112,15 @@ export function resolveDay(isoDate: string): LiturgicalDay {
   let winner = result.winner;
   const commemorations = [...result.commemorations];
 
-  const yesterday = resolveNativeOccurrence(addDays(isoDate, -1));
+  const yesterdayIso = addDays(isoDate, -1);
+  const yesterday = resolveNativeOccurrence(yesterdayIso);
   if (yesterday.result.transfer?.direction === 'forward') {
-    winner = applyIncomingTransfer(yesterday.result.transfer.candidate, temporalCategory, winner, commemorations);
+    winner = applyIncomingTransfer(yesterday.result.transfer.candidate, temporalCategory, winner, commemorations, yesterdayIso);
   }
-  const tomorrow = resolveNativeOccurrence(addDays(isoDate, 1));
+  const tomorrowIso = addDays(isoDate, 1);
+  const tomorrow = resolveNativeOccurrence(tomorrowIso);
   if (tomorrow.result.transfer?.direction === 'backward') {
-    winner = applyIncomingTransfer(tomorrow.result.transfer.candidate, temporalCategory, winner, commemorations);
+    winner = applyIncomingTransfer(tomorrow.result.transfer.candidate, temporalCategory, winner, commemorations, tomorrowIso);
   }
 
   winner = applyOctaves(isoDate, winner, commemorations);
@@ -116,7 +131,13 @@ export function resolveDay(isoDate: string): LiturgicalDay {
   applyEpiphany6Commemoration(isoDate, commemorations);
   applyAdventFourVigilCommemoration(isoDate, weekday, commemorations);
 
-  return { date: isoDate, weekday, season, temporalCategory, winner, commemorations };
+  // This date's own native candidate (if any) couldn't be kept here and
+  // moved on instead — see calendar/types.ts's `transferredAway` doc
+  // comment for why this is tracked separately from `Commemoration`, and
+  // why no landing date is recorded.
+  const transferredAway = result.transfer ? { candidate: result.transfer.candidate } : undefined;
+
+  return { date: isoDate, weekday, season, temporalCategory, winner, commemorations, transferredAway };
 }
 
 /**

src/calendar/types.ts

@@ -161,6 +161,12 @@ export type DayWinner =
       // First Vespers is being anticipated this evening (i.e. this feast
       // belongs to *tomorrow*, but is winning tonight's Vespers/Compline).
       vespersFrom?: 'firstVespersOfTomorrow';
+      // Set by calendar/index.ts's resolveDay/applyIncomingTransfer when
+      // this winner is only here because its own native date (an adjacent
+      // ISO date) couldn't hold it (calendar/commemorations.ts's
+      // `decideOccurrence` `transfer` signal) — the ISO date it transferred
+      // *from*. Absent for a feast winning on its own native date.
+      transferredFrom?: string;
     } & SanctoralIdentity);
 
 /**
@@ -184,6 +190,14 @@ export type Commemoration =
       // commemoration (a real collision, an octave day, etc.), which
       // carries no such qualifier.
       vespersNote?: 'today' | 'tomorrow';
+      // Set by calendar/index.ts's applyIncomingTransfer, same meaning as
+      // `DayWinner`'s own `transferredFrom` — this saint is only
+      // commemorated here (rather than absent) because a transfer landed
+      // on this date and lost a collision, or fell below the landing
+      // day's own outright-winning threshold, not because it's natively
+      // due for commemoration here. Absent for an ordinary same-day
+      // commemoration.
+      transferredFrom?: string;
     } & SanctoralIdentity)
   | { kind: 'octave'; id: string; name: string; nameLa?: string };
 
@@ -199,4 +213,16 @@ export interface LiturgicalDay {
   winner: DayWinner;
   /** Everything else commemorated alongside the winner — see the doc comment on Commemoration. */
   commemorations: Commemoration[];
+  /** Set when this date's own native sanctoral candidate couldn't be kept
+   * here at all (calendar/commemorations.ts's `decideOccurrence` `transfer`
+   * signal) and moved to a later/earlier date instead. No landing date is
+   * recorded here — `resolveDay` only ever checks the immediate adjacent
+   * date, but a real landing can chain further than that (an unmodeled
+   * case noted in `applyIncomingTransfer`, e.g. a transfer running into
+   * Holy Week), so naming a specific "to" date risked asserting a wrong
+   * one; this exists purely so the display can say "not an omission, this
+   * office moved elsewhere" without claiming to know where. Distinct from
+   * — and not implied by — `Commemoration`, since a transferred-away
+   * candidate gets no commemoration on its own native date at all. */
+  transferredAway?: { candidate: SanctoralIdentity };
 }

tests/calendar/april-sanctoral.test.ts

@@ -45,7 +45,14 @@ describe('April sanctoral pull (first pass)', () => {
     ]);
 
     const monday = resolveDay('2029-04-30');
-    expect(monday.winner).toEqual({ kind: 'sanctoral', id: 'st-robert', name: 'St. Robert, Abbot', nameLa: 'Sanctus Robertus, Abbas', rank: 'duplex' });
+    expect(monday.winner).toEqual({
+      kind: 'sanctoral',
+      id: 'st-robert',
+      name: 'St. Robert, Abbot',
+      nameLa: 'Sanctus Robertus, Abbas',
+      rank: 'duplex',
+      transferredFrom: '2029-04-29',
+    });
     expect(monday.commemorations).toEqual([
       { kind: 'sanctoral', id: 'st-peter-martyr', name: 'St. Peter Martyr, Martyr', nameLa: 'Sanctus Petrus Martyr, Martyr', rank: 'semiduplex' },
     ]);

tests/calendar/day-label.test.ts

@@ -34,8 +34,12 @@ describe('getDayLabel — ordinal temporal label', () => {
     expect(getDayLabel(resolveDay('2026-05-31')).en).toBe(
       'The Queenship of the Blessed Virgin Mary (Duplex II Class) — Trinity Sunday',
     );
-    expect(getDayLabel(resolveDay('2026-04-05')).en).toBe('Easter (Duplex I Class)');
-    expect(getDayLabel(resolveDay('2026-02-18')).en).toBe('Ash Wednesday');
+    expect(getDayLabel(resolveDay('2026-04-05')).en).toBe(
+      "Easter (Duplex I Class) — St. Vincent Ferrer, Confessor (transferred away)",
+    );
+    expect(getDayLabel(resolveDay('2026-02-18')).en).toBe(
+      "Ash Wednesday — St. Simeon, Bishop and Martyr (transferred away)",
+    );
     // Latin: the winner now has a real authored nameLa (see
     // calendar/data/calendar/saints/queenship-of-the-bvm.yml), so this is
     // real Latin throughout — the rank label ("Duplex II. Classis") and
@@ -44,8 +48,12 @@ describe('getDayLabel — ordinal temporal label', () => {
     expect(getDayLabel(resolveDay('2026-05-31')).la).toBe(
       'Beata Maria Virgo Regina (Duplex II. Classis) — Dominica Sanctissimae Trinitatis',
     );
-    expect(getDayLabel(resolveDay('2026-04-05')).la).toBe('Pascha (Duplex I. Classis)');
-    expect(getDayLabel(resolveDay('2026-02-18')).la).toBe('Feria Quarta Cinerum');
+    expect(getDayLabel(resolveDay('2026-04-05')).la).toBe(
+      'Pascha (Duplex I. Classis) — Sanctus Vincentius Ferrerius, Confessor (translata alio)',
+    );
+    expect(getDayLabel(resolveDay('2026-02-18')).la).toBe(
+      'Feria Quarta Cinerum — Sanctus Simeon, Episcopus et Martyr (translata alio)',
+    );
   });
 
   it('gives the correct week-after-Trinity ordinal', () => {
@@ -117,7 +125,9 @@ describe('getDayLabel — resumed post-Epiphany Sunday (overflow years)', () =>
     expect(getDayLabel(resolveDay('2024-11-11')).en).toBe(
       'St. Martin of Tours, Bishop and Confessor (Duplex Majus) — St. Menna, Martyr',
     );
-    expect(getDayLabel(resolveDay('2024-11-17')).en).toBe('The 6th Sunday after Epiphany (Semiduplex)');
+    expect(getDayLabel(resolveDay('2024-11-17')).en).toBe(
+      "The 6th Sunday after Epiphany (Semiduplex) — St. Gregory Thaumaturgus, Bishop and Confessor (transferred away)",
+    );
     // 2024-11-18 is the Dedication of the Basilicas of Ss. Peter and Paul
     // (pre-existing fixed content) -- again a real winning saint, not the
     // ferial fallback -- with St. Gregory Thaumaturgus (Semiduplex,
@@ -126,7 +136,7 @@ describe('getDayLabel — resumed post-Epiphany Sunday (overflow years)', () =>
     // transfers to the next open day rather than being commemorated in
     // place, and Nov 18 is that day.
     expect(getDayLabel(resolveDay('2024-11-18')).en).toBe(
-      'Dedication of the Basilicas of Ss. Peter and Paul (Duplex) — St. Gregory Thaumaturgus, Bishop and Confessor',
+      'Dedication of the Basilicas of Ss. Peter and Paul (Duplex) — St. Gregory Thaumaturgus, Bishop and Confessor (transferred)',
     );
     // 2035-10-29, a Monday in the 3rd week of a different overflow
     // stretch, is genuinely clean (no sanctoral entry, no commemoration)
@@ -147,9 +157,11 @@ describe('getDayLabel — resumed post-Epiphany Sunday (overflow years)', () =>
     // Thaumaturgus above -- landing on 2026-11-23 instead, where St.
     // Clement already natively wins; Cecilia loses that tied collision
     // (both Semiduplex) and joins St. Felicitas as a commemoration there.
-    expect(getDayLabel(resolveDay('2026-11-22')).en).toBe('The 23rd Sunday after Trinity (Semiduplex)');
+    expect(getDayLabel(resolveDay('2026-11-22')).en).toBe(
+      "The 23rd Sunday after Trinity (Semiduplex) — St. Cecilia, Virgin and Martyr (transferred away)",
+    );
     expect(getDayLabel(resolveDay('2026-11-23')).en).toBe(
-      'St. Clement I, Pope and Martyr (Semiduplex) — St. Felicitas, Martyr — St. Cecilia, Virgin and Martyr',
+      'St. Clement I, Pope and Martyr (Semiduplex) — St. Felicitas, Martyr — St. Cecilia, Virgin and Martyr (transferred)',
     );
     // 1943-11-21 is also the Presentation of the BVM (Duplex Majus, added
     // 2026-08 — see presentation-of-the-bvm.yml). It's `ordinary-sunday`
@@ -399,7 +411,7 @@ describe('getDayLabel/getVespersStatusLabel — Vespers evening with a temporal
     expect(day.date).toBe('2026-08-30');
     expect(day.winner).toEqual({ kind: 'temporal', id: 'post-pentecost-14' });
     expect(getDayLabel(day).en).toBe(
-      'The 13th Sunday after Trinity (Semiduplex) — Ss. Felix and Adauctus, Martyrs — The Beheading of St. John the Baptist (of today)',
+      "The 13th Sunday after Trinity (Semiduplex) — Ss. Felix and Adauctus, Martyrs — The Beheading of St. John the Baptist (of today) — St. Rose of Lima, Virgin (transferred away)",
     );
     expect(getVespersStatusLabel(day, '2026-08-29').en).toBe('First Vespers (of tomorrow)');
   });

tests/calendar/november-sanctoral.test.ts

@@ -85,6 +85,7 @@ describe('November sanctoral pull (first pass)', () => {
       name: 'St. Clement I, Pope and Martyr',
       nameLa: 'Sanctus Clemens I, Papa et Martyr',
       rank: 'semiduplex',
+      transferredFrom: '2025-11-23',
     });
     expect(followingDay.commemorations).toEqual([
       { kind: 'sanctoral', id: 'st-chrysogonus', name: 'St. Chrysogonus, Martyr', nameLa: 'Sanctus Chrysogonus, Martyr', rank: 'simplex' },

tests/calendar/september-sanctoral.test.ts

@@ -28,6 +28,7 @@ describe('September sanctoral pull (first pass)', () => {
       name: 'St. Raymond Nonnatus, Confessor',
       nameLa: 'Sanctus Raymundus Nonnatus, Confessor',
       rank: 'semiduplex',
+      transferredFrom: '2025-08-31',
     });
     expect(day.commemorations).toEqual([
       { kind: 'sanctoral', id: 'ss-twelve-brothers', name: 'Ss. Twelve Brothers, Martyrs', nameLa: 'Duodecim Fratres, Martyres', rank: 'simplex' },

tests/calendar/transfer.test.ts

@@ -28,7 +28,14 @@ describe('transfer mechanism (resolveDay integration)', () => {
       rank: 'semiduplex',
     });
     expect(saturday.commemorations).toEqual([
-      { kind: 'sanctoral', id: 'vigil-of-st-lawrence', name: 'Vigil of St. Lawrence', nameLa: 'Vigilia Sancti Laurentii', rank: 'vigil' },
+      {
+        kind: 'sanctoral',
+        id: 'vigil-of-st-lawrence',
+        name: 'Vigil of St. Lawrence',
+        nameLa: 'Vigilia Sancti Laurentii',
+        rank: 'vigil',
+        transferredFrom: '2026-08-09',
+      },
     ]);
 
     // The Sunday's own winner is unaffected by the vigil, but St. Romanus