diff --git a/components/email/__tests__/invitation-series-ux-p2-pim.test.tsx b/components/email/__tests__/invitation-series-ux-p2-pim.test.tsx
new file mode 100644
index 000000000..df63353a9
--- /dev/null
+++ b/components/email/__tests__/invitation-series-ux-p2-pim.test.tsx
@@ -0,0 +1,262 @@
+import { render, screen, fireEvent, waitFor } from '@testing-library/react';
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { CalendarInvitationBanner } from '../calendar-invitation-banner';
+import type { Email } from '@/lib/jmap/types';
+
+const mocks = vi.hoisted(() => {
+  const pushMock = vi.fn();
+  const clientMock = {
+    parseCalendarEvents: vi.fn(),
+    getAccountId: vi.fn(() => 'mail-account'),
+    getCalendarsAccountId: vi.fn(() => 'calendar-account'),
+    getCalendarEvent: vi.fn(),
+    queryCalendarEvents: vi.fn(async (): Promise<unknown[]> => []),
+    // Who owns a shared or group account (Principal/get).
+    getAccountOwners: vi.fn(async (ids: string[]) => Object.fromEntries(ids.map((id) => [id, id === 'team'
+      ? { id, type: 'group', name: 'team@example.com', email: 'team@example.com' }
+      : { id, type: 'individual', name: id + '@example.com', email: id + '@example.com' }]))),
+  };
+
+  const sourceClientMock = {
+    parseCalendarEvents: vi.fn(),
+    fetchBlob: vi.fn(),
+    getAccountId: vi.fn(() => 'source-mail-account'),
+    getCalendarsAccountId: vi.fn(() => 'source-calendar-account'),
+  };
+
+  const authState = {
+    client: clientMock,
+    primaryIdentity: { email: 'user@example.com' },
+    identities: [{ email: 'user@example.com' }] as Array<{ email: string }>,
+    getClientForAccount: vi.fn((id: string) => (id === 'login-b' ? sourceClientMock : undefined)),
+  };
+
+  const emailState = {
+    viewingAccountId: null as string | null,
+    selectedMailbox: 'inbox',
+    mailboxes: [] as Array<Record<string, unknown>>,
+    accountMailboxes: {} as Record<string, Array<Record<string, unknown>>>,
+  };
+
+  const settingsState = {
+    calendarInvitationParsingEnabled: true,
+  };
+
+  const calendarState = {
+    calendars: [{ id: 'cal-1', name: 'Primary', color: '#2563eb', isDefault: true }],
+    supportsCalendar: true,
+    importEvents: vi.fn(),
+    rsvpEvent: vi.fn(),
+    updateEvent: vi.fn(),
+    deleteEvent: vi.fn(),
+    events: [] as Array<Record<string, unknown>>,
+    setSelectedDate: vi.fn(),
+  };
+
+  const useCalendarStoreMock = ((selector?: (state: typeof calendarState) => unknown) => (
+    typeof selector === 'function' ? selector(calendarState) : calendarState
+  )) as {
+    (selector?: (state: typeof calendarState) => unknown): unknown;
+    getState: () => typeof calendarState;
+    setState: (updater: Partial<typeof calendarState> | ((state: typeof calendarState) => Partial<typeof calendarState> | typeof calendarState)) => void;
+  };
+
+  useCalendarStoreMock.getState = () => calendarState;
+  useCalendarStoreMock.setState = (updater) => {
+    const nextState = typeof updater === 'function' ? updater(calendarState) : updater;
+    Object.assign(calendarState, nextState);
+  };
+
+  return {
+    pushMock,
+    clientMock,
+    sourceClientMock,
+    authState,
+    emailState,
+    settingsState,
+    calendarState,
+    useCalendarStoreMock,
+  };
+});
+
+vi.mock('next-intl', () => ({
+  useTranslations: () => (key: string, values?: Record<string, string>) => {
+    const strings: Record<string, string> = {
+      loading: 'Loading event details…',
+      title: 'Calendar Invitation',
+      organizer: 'Organized by {name}',
+      attendees: 'attendees',
+      add_to_calendar: 'Add to calendar',
+      added: 'Added to calendar',
+      rsvp_sent: 'Response sent',
+      already_in_calendar: 'Already in your calendar',
+      your_response: 'Your response: {status}',
+      response_accepted: 'Accepted',
+      response_needed: 'Needs response',
+      actor_response_info: '{name} responded {status}.',
+      actor_sent_info: 'Sent by {name}.',
+      actor_counter_info: '{name} proposed changes to this event.',
+      actor_refresh_info: '{name} asked for the latest event details.',
+      actor_declined_counter_info: '{name} declined the counter proposal.',
+      actor_note: 'Note: {comment}',
+      actor_unknown: 'Someone',
+      sender_mismatch_unverified_info: 'This invitation was sent from {sender}, while the organizer listed in the calendar data is {organizer}, and the message could not be verified.',
+      attendee_mismatch_unverified_info: 'This response was sent from {sender}, while the attendee answering in the calendar data is {attendee}, and the message could not be verified.',
+      action_failed: 'Could not complete that calendar action.',
+      proposal_applied: 'Proposed changes applied.',
+      proposed_changes: 'Proposed changes',
+      change_title: 'Title',
+      change_time: 'Time',
+      change_location: 'Location',
+      change_description: 'Description',
+      change_empty: 'None',
+      change_from_to: '{before} -> {after}',
+      apply_proposal: 'Apply proposed changes',
+      review_proposal: 'Review proposal',
+      review_request: 'Review request',
+      view_in_calendar: 'View in calendar',
+      organizer_role: 'You organize this event',
+      accept: 'Accept',
+      maybe: 'Maybe',
+      decline: 'Decline',
+      select_calendar: 'Select calendar',
+      participant_limit: 'The server allows at most {max} participants per event.',
+      answered_accepted: 'You accepted on {date}.',
+      answered_declined: 'You declined on {date}.',
+      response_declined: 'Declined',
+      request_info: 'Respond to let the organizer know.',
+      repeats: 'Repeats: {rule}',
+      declined_dates: 'You declined {dates}.',
+      declined_many: 'You declined {count} meetings of this series.',
+      answers_series: 'Your answer is for every meeting in the series.',
+      'recurrence.weekly': 'Weekly',
+      'recurrence.on_days': 'on {days}',
+    };
+
+    let message = strings[key] ?? key;
+    if (values) {
+      for (const [name, value] of Object.entries(values)) {
+        message = message.replace(`{${name}}`, String(value));
+      }
+    }
+    return message;
+  },
+  useLocale: () => 'en-US',
+  useFormatter: () => ({
+    dateTime: (date: Date) => date.toISOString(),
+  }),
+}));
+
+vi.mock('@/i18n/navigation', () => ({
+  useRouter: () => ({ push: mocks.pushMock }),
+}));
+
+vi.mock('@/stores/auth-store', () => ({
+  useAuthStore: (selector: (state: typeof mocks.authState) => unknown) => selector(mocks.authState),
+}));
+
+vi.mock('@/stores/email-store', () => ({
+  useEmailStore: (selector: (state: typeof mocks.emailState) => unknown) => selector(mocks.emailState),
+}));
+
+vi.mock('@/stores/settings-store', () => ({
+  useSettingsStore: (selector: (state: typeof mocks.settingsState) => unknown) => selector(mocks.settingsState),
+}));
+
+vi.mock('@/stores/calendar-store', () => ({
+  useCalendarStore: mocks.useCalendarStoreMock,
+}));
+
+function makeEmail(overrides: Partial<Email> = {}): Email {
+  return {
+    id: 'email-1',
+    threadId: 'thread-1',
+    mailboxIds: { inbox: true },
+    keywords: {},
+    size: 512,
+    receivedAt: '2026-03-16T10:00:00Z',
+    hasAttachment: true,
+    attachments: [
+      {
+        partId: '1',
+        blobId: 'blob-1',
+        size: 256,
+        type: 'text/calendar; method=REQUEST',
+        name: 'invite.ics',
+      },
+    ],
+    ...overrides,
+  };
+}
+
+// pim-p2-8 (and pim-23): a weekly invitation where one week was declined said
+// "Your response: Declined. You declined on Wed, Nov 4." while the calendar
+// showed the following weeks unanswered, and nothing said it repeats. The
+// card now reads the series as stored: its own answer, the declined weeks by
+// date, that it repeats, and that the buttons answer every week.
+
+const me = { '@type': 'Participant', email: 'user@example.com', name: 'User', roles: { attendee: true }, participationStatus: 'needs-action' };
+const ben = { '@type': 'Participant', email: 'ben@example.com', name: 'Ben', roles: { owner: true, attendee: true }, participationStatus: 'accepted' };
+const rule = { '@type': 'RecurrenceRule', frequency: 'weekly', byDay: [{ '@type': 'NDay', day: 'tu' }] };
+const invitation = {
+  uid: 'weekly-1', title: 'Weekly sync with Ben', start: '2026-11-03T16:00:00', duration: 'PT30M', timeZone: 'Europe/Berlin',
+  recurrenceRules: [rule], participants: { me, ben },
+};
+// The series as Stalwart 1.0 stores it: Nov 3 declined on its own, as a pointer patch.
+const master = {
+  id: 'series-1', uid: 'weekly-1', title: 'Weekly sync with Ben', start: '2026-11-03T16:00:00', duration: 'PT30M',
+  timeZone: 'Europe/Berlin', recurrenceRules: [rule], participants: { me, ben },
+  recurrenceOverrides: { '2026-11-03T16:00:00': { 'participants/me/participationStatus': 'declined' } },
+};
+// What the grid holds: the expanded occurrences, the declined one first.
+const nov3 = {
+  ...master, id: 'occ-nov3', recurrenceId: '2026-11-03T16:00:00', recurrenceOverrides: null,
+  participants: { me: { ...me, participationStatus: 'declined' }, ben }, updated: '2026-11-04T09:00:00Z',
+};
+const nov10 = { ...master, id: 'occ-nov10', recurrenceId: '2026-11-10T16:00:00', start: '2026-11-10T16:00:00', recurrenceOverrides: null };
+
+describe('an invitation to a series', () => {
+  beforeEach(() => {
+    mocks.settingsState.calendarInvitationParsingEnabled = true;
+    mocks.clientMock.parseCalendarEvents.mockReset();
+    mocks.clientMock.queryCalendarEvents.mockReset();
+    mocks.calendarState.rsvpEvent.mockReset();
+    mocks.calendarState.events = [nov3, nov10] as never;
+    mocks.clientMock.parseCalendarEvents.mockResolvedValue([invitation]);
+    mocks.clientMock.queryCalendarEvents.mockImplementation(async () => [master]);
+    mocks.authState.identities = [{ email: 'user@example.com' }];
+  });
+
+  it("shows the series' own answer and the declined week by its date", async () => {
+    render(<CalendarInvitationBanner email={makeEmail()} />);
+    expect(await screen.findByText('You declined Nov 3.')).toBeInTheDocument();
+    expect(screen.queryByText('Your response: Declined')).not.toBeInTheDocument();
+    expect(screen.queryByText(/^You declined on/)).not.toBeInTheDocument();
+    expect(screen.getByText('Your response: Needs response')).toBeInTheDocument();
+    expect(mocks.clientMock.queryCalendarEvents).toHaveBeenCalledWith({ uid: 'weekly-1' });
+  });
+
+  it('says that it repeats, and that an answer is for every week', async () => {
+    render(<CalendarInvitationBanner email={makeEmail()} />);
+    expect(await screen.findByTestId('invitation-repeats')).toHaveTextContent('Repeats: Weekly on Tue');
+    expect(await screen.findByText('Your answer is for every meeting in the series.')).toBeInTheDocument();
+  });
+
+  it('answers the series, not the week the calendar held first', async () => {
+    mocks.calendarState.rsvpEvent.mockResolvedValue(true);
+    render(<CalendarInvitationBanner email={makeEmail()} />);
+    await screen.findByText('You declined Nov 3.');
+    fireEvent.click(screen.getByText('Accept'));
+    await waitFor(() => expect(mocks.calendarState.rsvpEvent).toHaveBeenCalled());
+    expect(mocks.calendarState.rsvpEvent.mock.calls[0][1]).toBe('series-1');
+    expect(mocks.calendarState.rsvpEvent.mock.calls[0][3]).toBe('accepted');
+  });
+
+  it('leaves a one-off invitation as it was', async () => {
+    mocks.clientMock.parseCalendarEvents.mockResolvedValue([{ ...invitation, uid: 'once', recurrenceRules: null }]);
+    render(<CalendarInvitationBanner email={makeEmail()} />);
+    await screen.findByText('Weekly sync with Ben');
+    expect(screen.queryByTestId('invitation-repeats')).not.toBeInTheDocument();
+    expect(screen.queryByTestId('invitation-answers-series')).not.toBeInTheDocument();
+  });
+});
diff --git a/components/email/calendar-invitation-banner.tsx b/components/email/calendar-invitation-banner.tsx
index 5928868d5..c794eac84 100644
--- a/components/email/calendar-invitation-banner.tsx
+++ b/components/email/calendar-invitation-banner.tsx
@@ -18,6 +18,7 @@ import {
   AlertCircle,
   ChevronDown,
   ChevronUp,
+  Repeat,
 } from '@/components/icons';
 import { useTranslations, useLocale } from 'next-intl';
 import { InvitationPrintSync } from '@/lib/print/invitation-print';
@@ -39,6 +40,8 @@ import {
   invitationAnsweredAt,
   invitationAnsweredKey,
   findParticipantByEmails,
+  isSeriesInvitation,
+  seriesAnswers,
   extractMethodFromRawIcs,
   type EventSummary,
   type InvitationMethod,
@@ -55,6 +58,7 @@ import { useCalendarErrorMessage } from '@/hooks/use-calendar-error-message';
 import { useAccountOwner } from '@/components/calendar/answer-bars';
 import { useCollectionNames } from "@/hooks/use-collection-names";
 import { resolveTimeZone } from '@/lib/timezone';
+import { buildRecurrenceSummary } from '@/components/calendar/recurrence-editor';
 
 interface InvitationChangeItem {
   label: string;
@@ -384,6 +388,8 @@ export function CalendarInvitationBanner({ email }: CalendarInvitationBannerProp
   const shownName = useCollectionNames();
   const t = useTranslations('email_viewer.calendar_invitation');
   const tEvent = useTranslations('ux_pim_event');
+  const tCalendar = useTranslations('calendar');
+  const tSeries = useTranslations('ux_p2_pim_calx');
   const describeError = useCalendarErrorMessage();
   const locale = useLocale();
   const router = useRouter();
@@ -479,6 +485,10 @@ export function CalendarInvitationBanner({ email }: CalendarInvitationBannerProp
   // What removing a cancelled meeting from the calendar takes, read from the
   // events stored with its uid; null until known.
   const [cancelRemoval, setCancelRemoval] = useState<CancellationRemoval | null>(null);
+  // An invitation to a series is answered as a series (pim-p2-8): the series as
+  // stored, with the occurrences answered on their own. The calendar holds the
+  // occurrences, and the first of them was read as the answer.
+  const [seriesMaster, setSeriesMaster] = useState<CalendarEvent | null>(null);
 
   const attachment = findCalendarAttachment(email);
 
@@ -577,6 +587,20 @@ export function CalendarInvitationBanner({ email }: CalendarInvitationBannerProp
   const method = detectedMethod !== 'unknown' ? detectedMethod : rawIcsMethod;
   const isCancellation = method === 'cancel';
 
+  const seriesUid = isSeriesInvitation(parsedEvent) ? parsedEvent?.uid ?? null : null;
+  useEffect(() => {
+    setSeriesMaster(null);
+    if (!client || !supportsCalendar || !seriesUid || sharedMailAccount) return;
+    let current = true;
+    client.queryCalendarEvents({ uid: seriesUid })
+      .then((stored) => {
+        const master = stored.find((e) => e.uid === seriesUid && !e.recurrenceId && !e.isShared) ?? null;
+        if (current) setSeriesMaster(master);
+      })
+      .catch(() => { /* the occurrence the calendar holds stands in */ });
+    return () => { current = false; };
+  }, [client, supportsCalendar, seriesUid, sharedMailAccount]);
+
   useEffect(() => {
     setCancelRemoval(null);
     if (!client || !supportsCalendar || !isCancellation || !parsedEvent?.uid) return;
@@ -634,9 +658,14 @@ export function CalendarInvitationBanner({ email }: CalendarInvitationBannerProp
   // answering there would answer for them (or, on Stalwart 0.16, for
   // whichever address it picks; the duplicate attendees and wrong senders of
   // #634).
-  const existingEvent = parsedEvent?.uid
+  const storedCopy = parsedEvent?.uid
     ? storeEvents.find((e) => e.uid === parsedEvent.uid && (sharedMailAccount ? e.accountId === sharedMailAccount : !e.isShared))
     : null;
+  const existingEvent = seriesMaster ?? storedCopy;
+  const isSeries = isSeriesInvitation(parsedEvent);
+  const seriesRule = isSeries && parsedEvent?.recurrenceRules?.[0]
+    ? buildRecurrenceSummary(parsedEvent.recurrenceRules[0], tCalendar, locale)
+    : null;
 
   const currentUserParticipant = existingEvent
     ? findParticipantByEmails(existingEvent, actingEmails)
@@ -679,6 +708,21 @@ export function CalendarInvitationBanner({ email }: CalendarInvitationBannerProp
     })
     : null;
   const bannerInfo = answeredInfo ?? getBannerInfo(t, method, userIsOrganizer, supportsCalendar);
+  // "You declined Nov 3": the weeks answered no on their own, by their date.
+  const declinedOccurrences = seriesMaster && method === 'request' && !rsvpStatus
+    ? seriesAnswers(seriesMaster, actingEmails).declined
+    : [];
+  const occurrenceDate = (recurrenceId: string) => {
+    const at = new Date(`${recurrenceId.slice(0, 19)}Z`);
+    return isNaN(at.getTime()) ? recurrenceId : new Intl.DateTimeFormat(locale, { month: 'short', day: 'numeric', timeZone: 'UTC' }).format(at);
+  };
+  const declinedInfo = declinedOccurrences.length === 0
+    ? null
+    : declinedOccurrences.length > 3
+      ? tSeries('declined_many', { count: declinedOccurrences.length })
+      : tSeries('declined_dates', {
+        dates: new Intl.ListFormat(locale, { type: 'conjunction' }).format(declinedOccurrences.map(occurrenceDate)),
+      });
   const trustAssessment = parsedEvent && !userIsSender ? getInvitationTrustAssessment(parsedEvent, email, method, identityEmails) : null;
   const trustMessage = trustAssessment ? getTrustMessage(t, trustAssessment) : null;
   const participationLabel = getParticipationLabel(t, currentRsvp);
@@ -1043,6 +1087,12 @@ export function CalendarInvitationBanner({ email }: CalendarInvitationBannerProp
                 </span>
               </span>
             )}
+            {seriesRule && (
+              <span className="flex items-center gap-1.5 min-w-0" data-testid="invitation-repeats">
+                <Repeat className="w-3.5 h-3.5 flex-shrink-0" />
+                <span className="truncate">{tSeries('repeats', { rule: seriesRule })}</span>
+              </span>
+            )}
             {summary.location && (
               <span className="flex items-center gap-1.5 min-w-0">
                 <MapPin className="w-3.5 h-3.5 flex-shrink-0" />
@@ -1112,9 +1162,10 @@ export function CalendarInvitationBanner({ email }: CalendarInvitationBannerProp
         )}
 
         {/* Info / actor messages */}
-        {showDetails && (bannerInfo || actorMessage || actorSummary?.participationComment) && (
+        {showDetails && (bannerInfo || declinedInfo || actorMessage || actorSummary?.participationComment) && (
           <div className="space-y-0.5 text-xs text-muted-foreground">
             {bannerInfo && <p className="leading-relaxed">{bannerInfo}</p>}
+            {declinedInfo && <p className="leading-relaxed" data-testid="invitation-declined-occurrences">{declinedInfo}</p>}
             {cancellationOutdated && <p className="leading-relaxed">{t('cancel_outdated')}</p>}
             {actorMessage && <p>{actorMessage}</p>}
             {actorSummary?.participationComment && (
@@ -1206,6 +1257,9 @@ export function CalendarInvitationBanner({ email }: CalendarInvitationBannerProp
                 <X className="w-3.5 h-3.5" />
                 {t('decline')}
               </button>
+              {isSeries && (
+                <span className="text-xs text-muted-foreground" data-testid="invitation-answers-series">{tSeries('answers_series')}</span>
+              )}
               <div className="w-px h-5 bg-border mx-1" />
             </>
           )}
diff --git a/lib/__tests__/series-answers-ux-p2-pim.test.ts b/lib/__tests__/series-answers-ux-p2-pim.test.ts
new file mode 100644
index 000000000..f1f66fe95
--- /dev/null
+++ b/lib/__tests__/series-answers-ux-p2-pim.test.ts
@@ -0,0 +1,48 @@
+import { describe, expect, it } from 'vitest';
+import { isSeriesInvitation, seriesAnswers } from '../calendar-invitation';
+import type { CalendarEvent } from '@/lib/jmap/types';
+
+// pim-p2-8: the series' own answer, and the occurrences declined on their own.
+// Stalwart 1.0 stores an occurrence's answer as a pointer patch, 0.16 as the
+// whole participants map.
+
+const me = { '@type': 'Participant', email: 'me@example.org', roles: { attendee: true }, participationStatus: 'accepted' };
+const ben = { '@type': 'Participant', email: 'ben@example.org', roles: { owner: true }, participationStatus: 'accepted' };
+
+function series(overrides: Record<string, unknown>): Partial<CalendarEvent> {
+  return {
+    uid: 'w', start: '2026-11-03T16:00:00', recurrenceRules: [{ frequency: 'weekly' }],
+    participants: { me, ben }, recurrenceOverrides: overrides,
+  } as unknown as Partial<CalendarEvent>;
+}
+
+describe('seriesAnswers', () => {
+  it('reads a pointer patch (Stalwart 1.0)', () => {
+    const result = seriesAnswers(series({
+      '2026-11-17T16:00:00': { 'participants/me/participationStatus': 'declined' },
+      '2026-11-03T16:00:00': { 'participants/me/participationStatus': 'declined' },
+      '2026-11-10T16:00:00': { title: 'Moved room' },
+    }), ['me@example.org']);
+    expect(result).toEqual({ status: 'accepted', declined: ['2026-11-03T16:00:00', '2026-11-17T16:00:00'] });
+  });
+
+  it('reads a whole participants map (Stalwart 0.16) and skips removed weeks', () => {
+    const result = seriesAnswers(series({
+      '2026-11-03T16:00:00': { participants: { me: { ...me, participationStatus: 'declined' }, ben } },
+      '2026-11-10T16:00:00': { excluded: true },
+    }), ['ME@example.org']);
+    expect(result).toEqual({ status: 'accepted', declined: ['2026-11-03T16:00:00'] });
+  });
+
+  it('lists none when the whole series is declined', () => {
+    const declined = { ...me, participationStatus: 'declined' };
+    const event = { ...series({ '2026-11-03T16:00:00': { 'participants/me/participationStatus': 'declined' } }), participants: { me: declined, ben } };
+    expect(seriesAnswers(event as unknown as Partial<CalendarEvent>, ['me@example.org'])).toEqual({ status: 'declined', declined: [] });
+  });
+
+  it('tells a series invitation from one for a single occurrence', () => {
+    expect(isSeriesInvitation(series({}))).toBe(true);
+    expect(isSeriesInvitation({ ...series({}), recurrenceId: '2026-11-03T16:00:00' } as Partial<CalendarEvent>)).toBe(false);
+    expect(isSeriesInvitation({ uid: 'x' })).toBe(false);
+  });
+});
diff --git a/lib/calendar-invitation.ts b/lib/calendar-invitation.ts
index 60fdff12b..0c16debea 100644
--- a/lib/calendar-invitation.ts
+++ b/lib/calendar-invitation.ts
@@ -2,6 +2,7 @@ import type { Email, Attachment, CalendarEvent, CalendarParticipant, EmailBodyPa
 import { normalizeCalendarEventLike } from '@/lib/calendar-event-normalization';
 import { hasAlignedAuthenticationPass } from '@/lib/email-headers';
 import { fromWallClock, getTimeZoneOffsetMs, isValidTimeZone, parseLocalDateTime, type WallClock } from '@/lib/timezone';
+import { applyOverridePatch } from '@/lib/recurrence-instances';
 
 export type InvitationMethod =
   | 'publish'
@@ -797,6 +798,35 @@ export function invitationAnsweredAt(
  * user's identities, primary first: an invite may be addressed to an alias
  * identity rather than the primary address (#1283).
  */
+/**
+ * An invitation to a series is answered as a series: the answer is the series'
+ * own, and occurrences answered no on their own are listed apart (pim-p2-8).
+ * The card said "You declined" for a weekly meeting when one week was declined,
+ * read from whichever occurrence the calendar held first. `master` is the
+ * series as stored, with its recurrenceOverrides; `declined` holds the
+ * recurrence ids (wall clock in the event's zone), oldest first.
+ */
+export function seriesAnswers(
+  master: Partial<CalendarEvent>,
+  emails: readonly string[],
+): { status: string | null; declined: string[] } {
+  const own = findParticipantByEmails(master, emails);
+  const status = own?.participant.participationStatus ?? null;
+  const declined: string[] = [];
+  for (const [recurrenceId, patch] of Object.entries(master.recurrenceOverrides ?? {})) {
+    if (!patch || typeof patch !== 'object' || (patch as { excluded?: unknown }).excluded === true) continue;
+    const occurrence = applyOverridePatch(master, patch as Record<string, unknown>);
+    const mine = findParticipantByEmails(occurrence, emails);
+    if (mine?.participant.participationStatus === 'declined' && status !== 'declined') declined.push(recurrenceId);
+  }
+  return { status, declined: declined.sort() };
+}
+
+/** Whether a parsed invitation is for a whole series, not one occurrence of it. */
+export function isSeriesInvitation(event: Partial<CalendarEvent> | null | undefined): boolean {
+  return !!event?.recurrenceRules?.length && !event.recurrenceId;
+}
+
 export function findParticipantByEmails(
   event: Partial<CalendarEvent>,
   emails: readonly string[]
diff --git a/locales/ar/common.json b/locales/ar/common.json
index db3f91ff9..b3d2379d4 100644
--- a/locales/ar/common.json
+++ b/locales/ar/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "رفضت الدعوة.",
     "answered_tentative_nodate": "أجبت بـ\"ربما\"."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "يتكرر: {rule}",
+    "declined_dates": "رفضت موعد {dates}.",
+    "declined_many": "رفضت {count} من مواعيد هذه السلسلة.",
+    "answers_series": "ينطبق ردك على كل مواعيد السلسلة."
+  },
   "calendar_event_notifications": {
     "someone": "شخص ما",
     "invited": "دعاك {name} إلى \"{title}\"",
diff --git a/locales/ca/common.json b/locales/ca/common.json
index 370dd4902..bdfacf30b 100644
--- a/locales/ca/common.json
+++ b/locales/ca/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Heu rebutjat.",
     "answered_tentative_nodate": "Heu respost potser."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Es repeteix: {rule}",
+    "declined_dates": "Has rebutjat el {dates}.",
+    "declined_many": "Has rebutjat {count} reunions d'aquesta sèrie.",
+    "answers_series": "La teva resposta val per a totes les reunions de la sèrie."
+  },
   "calendar_event_notifications": {
     "someone": "Algú",
     "invited": "{name} t'ha convidat a \"{title}\"",
diff --git a/locales/cs/common.json b/locales/cs/common.json
index c77cddf2a..40f6e5f45 100644
--- a/locales/cs/common.json
+++ b/locales/cs/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Odmítli jste.",
     "answered_tentative_nodate": "Odpověděli jste možná."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Opakuje se: {rule}",
+    "declined_dates": "Odmítli jste {dates}.",
+    "declined_many": "Odmítli jste {count} schůzek této série.",
+    "answers_series": "Vaše odpověď platí pro všechny schůzky série."
+  },
   "advanced_search": {
     "title": "Pokročilé hledání",
     "from": "Od",
diff --git a/locales/da/common.json b/locales/da/common.json
index 89522ce74..d9cb6b76c 100644
--- a/locales/da/common.json
+++ b/locales/da/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Du afslog.",
     "answered_tentative_nodate": "Du svarede måske."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Gentages: {rule}",
+    "declined_dates": "Du afslog {dates}.",
+    "declined_many": "Du afslog {count} møder i denne serie.",
+    "answers_series": "Dit svar gælder alle møder i serien."
+  },
   "calendar_event_notifications": {
     "someone": "Nogen",
     "invited": "{name} har inviteret dig til \"{title}\"",
diff --git a/locales/de/common.json b/locales/de/common.json
index 5f077d7fd..ec24e06d4 100644
--- a/locales/de/common.json
+++ b/locales/de/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Sie haben abgesagt.",
     "answered_tentative_nodate": "Sie haben mit Vielleicht geantwortet."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Wiederholung: {rule}",
+    "declined_dates": "Sie haben am {dates} abgesagt.",
+    "declined_many": "Sie haben {count} Termine dieser Serie abgesagt.",
+    "answers_series": "Ihre Antwort gilt für alle Termine der Serie."
+  },
   "advanced_search": {
     "title": "Erweiterte Suche",
     "from": "Von",
diff --git a/locales/en/common.json b/locales/en/common.json
index ea30812aa..0b497c13d 100644
--- a/locales/en/common.json
+++ b/locales/en/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "You declined.",
     "answered_tentative_nodate": "You answered maybe."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Repeats: {rule}",
+    "declined_dates": "You declined {dates}.",
+    "declined_many": "You declined {count} meetings of this series.",
+    "answers_series": "Your answer counts for every meeting in the series."
+  },
   "calendar_event_notifications": {
     "someone": "Someone",
     "invited": "{name} invited you to \"{title}\"",
diff --git a/locales/es/common.json b/locales/es/common.json
index e28d12f5f..9fefdd4b2 100644
--- a/locales/es/common.json
+++ b/locales/es/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Rechazaste.",
     "answered_tentative_nodate": "Respondiste quizás."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Se repite: {rule}",
+    "declined_dates": "Rechazaste el {dates}.",
+    "declined_many": "Rechazaste {count} reuniones de esta serie.",
+    "answers_series": "Tu respuesta vale para todas las reuniones de la serie."
+  },
   "advanced_search": {
     "title": "Búsqueda avanzada",
     "from": "De",
diff --git a/locales/et/common.json b/locales/et/common.json
index 584c4f2b7..fbcf3ab92 100644
--- a/locales/et/common.json
+++ b/locales/et/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Keeldusite.",
     "answered_tentative_nodate": "Vastasite võib-olla."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Kordub: {rule}",
+    "declined_dates": "Lükkasite tagasi kuupäeva {dates}.",
+    "declined_many": "Lükkasite tagasi {count} selle sarja kohtumist.",
+    "answers_series": "Teie vastus kehtib sarja kõigile kohtumistele."
+  },
   "calendar_event_notifications": {
     "someone": "Keegi",
     "invited": "{name} kutsus sind sündmusele \"{title}\"",
diff --git a/locales/fa/common.json b/locales/fa/common.json
index 1c49696fe..99f315963 100644
--- a/locales/fa/common.json
+++ b/locales/fa/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "رد کردید.",
     "answered_tentative_nodate": "پاسخ «شاید» دادید."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "تکرار: {rule}",
+    "declined_dates": "جلسهٔ {dates} را رد کردید.",
+    "declined_many": "{count} جلسه از این سری را رد کردید.",
+    "answers_series": "پاسخ شما برای همهٔ جلسه‌های این سری است."
+  },
   "calendar_event_notifications": {
     "someone": "کسی",
     "invited": "{name} شما را به «{title}» دعوت کرد",
diff --git a/locales/fr/common.json b/locales/fr/common.json
index 1a6a2f71c..f27b3f84e 100644
--- a/locales/fr/common.json
+++ b/locales/fr/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Vous avez refusé.",
     "answered_tentative_nodate": "Vous avez répondu peut-être."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Se répète : {rule}",
+    "declined_dates": "Vous avez refusé le {dates}.",
+    "declined_many": "Vous avez refusé {count} réunions de cette série.",
+    "answers_series": "Votre réponse vaut pour toutes les réunions de la série."
+  },
   "advanced_search": {
     "title": "Recherche avancée",
     "from": "De",
diff --git a/locales/he/common.json b/locales/he/common.json
index e15809a86..2a2eae497 100644
--- a/locales/he/common.json
+++ b/locales/he/common.json
@@ -5120,6 +5120,12 @@
     "answered_declined_nodate": "דחית.",
     "answered_tentative_nodate": "ענית 'אולי'."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "חוזר: {rule}",
+    "declined_dates": "דחית את {dates}.",
+    "declined_many": "דחית {count} פגישות בסדרה הזו.",
+    "answers_series": "התשובה שלך חלה על כל הפגישות בסדרה."
+  },
   "advanced_search": {
     "title": "חיפוש מתקדם",
     "from": "מ",
diff --git a/locales/hu/common.json b/locales/hu/common.json
index 23c5c88d4..957a4985e 100644
--- a/locales/hu/common.json
+++ b/locales/hu/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Ön elutasította.",
     "answered_tentative_nodate": "Ön talánnal válaszolt."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Ismétlődik: {rule}",
+    "declined_dates": "Elutasította: {dates}.",
+    "declined_many": "A sorozat {count} alkalmát utasította el.",
+    "answers_series": "A válasza a sorozat minden alkalmára vonatkozik."
+  },
   "calendar_event_notifications": {
     "someone": "Valaki",
     "invited": "{name} meghívott a(z) „{title}” eseményre",
diff --git a/locales/it/common.json b/locales/it/common.json
index 73fda3f89..9024cfbf1 100644
--- a/locales/it/common.json
+++ b/locales/it/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Hai rifiutato.",
     "answered_tentative_nodate": "Hai risposto forse."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Si ripete: {rule}",
+    "declined_dates": "Hai rifiutato il {dates}.",
+    "declined_many": "Hai rifiutato {count} riunioni di questa serie.",
+    "answers_series": "La tua risposta vale per tutte le riunioni della serie."
+  },
   "advanced_search": {
     "title": "Ricerca avanzata",
     "from": "Da",
diff --git a/locales/ja/common.json b/locales/ja/common.json
index 6b2f3e82b..2ade125ae 100644
--- a/locales/ja/common.json
+++ b/locales/ja/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "辞退しました。",
     "answered_tentative_nodate": "未定と回答しました。"
   },
+  "ux_p2_pim_calx": {
+    "repeats": "繰り返し: {rule}",
+    "declined_dates": "{dates} は辞退しました。",
+    "declined_many": "このシリーズの {count} 件を辞退しました。",
+    "answers_series": "回答はシリーズのすべての会議に適用されます。"
+  },
   "advanced_search": {
     "title": "詳細検索",
     "from": "差出人",
diff --git a/locales/ko/common.json b/locales/ko/common.json
index fe9560d3f..9a674b669 100644
--- a/locales/ko/common.json
+++ b/locales/ko/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "거절했습니다.",
     "answered_tentative_nodate": "미정으로 응답했습니다."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "반복: {rule}",
+    "declined_dates": "{dates} 일정을 거절했습니다.",
+    "declined_many": "이 시리즈의 일정 {count}개를 거절했습니다.",
+    "answers_series": "답변은 시리즈의 모든 일정에 적용됩니다."
+  },
   "advanced_search": {
     "title": "상세 검색",
     "from": "보낸 사람",
diff --git a/locales/lv/common.json b/locales/lv/common.json
index 6c2792f2a..abe70ff84 100644
--- a/locales/lv/common.json
+++ b/locales/lv/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Jūs noraidījāt.",
     "answered_tentative_nodate": "Jūs atbildējāt varbūt."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Atkārtojas: {rule}",
+    "declined_dates": "Jūs atteicāt {dates}.",
+    "declined_many": "Jūs atteicāt {count} šīs sērijas sapulces.",
+    "answers_series": "Jūsu atbilde attiecas uz visām sērijas sapulcēm."
+  },
   "advanced_search": {
     "title": "Izvērstā meklēšana",
     "from": "No",
diff --git a/locales/mn/common.json b/locales/mn/common.json
index 5638c0661..eded34e01 100644
--- a/locales/mn/common.json
+++ b/locales/mn/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Та татгалзсан.",
     "answered_tentative_nodate": "Та магадгүй гэж хариулсан."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Давтагдана: {rule}",
+    "declined_dates": "Та {dates}-ны уулзалтаас татгалзсан.",
+    "declined_many": "Та энэ цувралын {count} уулзалтаас татгалзсан.",
+    "answers_series": "Таны хариу цувралын бүх уулзалтад хамаарна."
+  },
   "calendar_event_notifications": {
     "someone": "Хэн нэгэн",
     "invited": "{name} таныг \"{title}\"-д урилаа",
diff --git a/locales/nb/common.json b/locales/nb/common.json
index 875523efe..a5d992a26 100644
--- a/locales/nb/common.json
+++ b/locales/nb/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Du avslo.",
     "answered_tentative_nodate": "Du svarte kanskje."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Gjentas: {rule}",
+    "declined_dates": "Du avslo {dates}.",
+    "declined_many": "Du avslo {count} møter i denne serien.",
+    "answers_series": "Svaret ditt gjelder alle møtene i serien."
+  },
   "calendar_event_notifications": {
     "someone": "Noen",
     "invited": "{name} har invitert deg til «{title}»",
diff --git a/locales/nl/common.json b/locales/nl/common.json
index c24f86f62..436a8fd2b 100644
--- a/locales/nl/common.json
+++ b/locales/nl/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Je hebt geweigerd.",
     "answered_tentative_nodate": "Je hebt misschien geantwoord."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Herhaalt: {rule}",
+    "declined_dates": "U hebt {dates} afgeslagen.",
+    "declined_many": "U hebt {count} afspraken van deze reeks afgeslagen.",
+    "answers_series": "Uw antwoord geldt voor alle afspraken in de reeks."
+  },
   "advanced_search": {
     "title": "Geavanceerd zoeken",
     "from": "Van",
diff --git a/locales/pl/common.json b/locales/pl/common.json
index 90a292bbd..2f576bb83 100644
--- a/locales/pl/common.json
+++ b/locales/pl/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Odrzucono.",
     "answered_tentative_nodate": "Odpowiedziano „może”."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Powtarza się: {rule}",
+    "declined_dates": "Odrzucono {dates}.",
+    "declined_many": "Odrzucono {count} spotkań z tej serii.",
+    "answers_series": "Twoja odpowiedź dotyczy wszystkich spotkań z serii."
+  },
   "advanced_search": {
     "title": "Wyszukiwanie zaawansowane",
     "from": "Od",
diff --git a/locales/pt/common.json b/locales/pt/common.json
index f38b2bc69..c346a8c8d 100644
--- a/locales/pt/common.json
+++ b/locales/pt/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Você recusou.",
     "answered_tentative_nodate": "Você respondeu talvez."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Repete-se: {rule}",
+    "declined_dates": "Você recusou {dates}.",
+    "declined_many": "Você recusou {count} reuniões desta série.",
+    "answers_series": "Sua resposta vale para todas as reuniões da série."
+  },
   "advanced_search": {
     "title": "Pesquisa avançada",
     "from": "De",
diff --git a/locales/ro/common.json b/locales/ro/common.json
index e0e5ef680..e305011c3 100644
--- a/locales/ro/common.json
+++ b/locales/ro/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Ai refuzat.",
     "answered_tentative_nodate": "Ai răspuns poate."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Se repetă: {rule}",
+    "declined_dates": "Ați refuzat {dates}.",
+    "declined_many": "Ați refuzat {count} întâlniri din această serie.",
+    "answers_series": "Răspunsul dvs. este pentru toate întâlnirile din serie."
+  },
   "calendar_event_notifications": {
     "someone": "Cineva",
     "invited": "{name} te-a invitat la „{title}”",
diff --git a/locales/ru/common.json b/locales/ru/common.json
index 761f4d4dd..4267d5329 100644
--- a/locales/ru/common.json
+++ b/locales/ru/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Вы отклонили.",
     "answered_tentative_nodate": "Вы ответили «может быть»."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Повторяется: {rule}",
+    "declined_dates": "Вы отклонили встречу {dates}.",
+    "declined_many": "Вы отклонили встреч этой серии: {count}.",
+    "answers_series": "Ваш ответ относится ко всем встречам серии."
+  },
   "advanced_search": {
     "title": "Расширенный поиск",
     "from": "От",
diff --git a/locales/sk/common.json b/locales/sk/common.json
index 5b1572ca2..23e545cd2 100644
--- a/locales/sk/common.json
+++ b/locales/sk/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Odmietli ste.",
     "answered_tentative_nodate": "Odpovedali ste možno."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Opakuje sa: {rule}",
+    "declined_dates": "Odmietli ste {dates}.",
+    "declined_many": "Odmietli ste {count} stretnutí tejto série.",
+    "answers_series": "Vaša odpoveď platí pre všetky stretnutia série."
+  },
   "calendar_event_notifications": {
     "someone": "Niekto",
     "invited": "{name} vás pozval(a) na „{title}“",
diff --git a/locales/th/common.json b/locales/th/common.json
index 4e7043c82..4a785f5fa 100644
--- a/locales/th/common.json
+++ b/locales/th/common.json
@@ -4638,6 +4638,12 @@
     "answered_declined_nodate": "คุณปฏิเสธแล้ว",
     "answered_tentative_nodate": "คุณตอบว่าอาจจะ"
   },
+  "ux_p2_pim_calx": {
+    "repeats": "ทำซ้ำ: {rule}",
+    "declined_dates": "คุณปฏิเสธวันที่ {dates}",
+    "declined_many": "คุณปฏิเสธ {count} การประชุมในชุดนี้",
+    "answers_series": "คำตอบของคุณใช้กับทุกการประชุมในชุดนี้"
+  },
   "settings": {
     "title": "การตั้งค่า",
     "org_locked": "กำหนดโดยองค์กรของคุณ",
diff --git a/locales/tr/common.json b/locales/tr/common.json
index ac8dd7b92..e4419a9d8 100644
--- a/locales/tr/common.json
+++ b/locales/tr/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Reddettiniz.",
     "answered_tentative_nodate": "Belki dediniz."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Tekrarlanır: {rule}",
+    "declined_dates": "{dates} toplantısını reddettiniz.",
+    "declined_many": "Bu serideki {count} toplantıyı reddettiniz.",
+    "answers_series": "Yanıtınız serideki tüm toplantılar için geçerlidir."
+  },
   "calendar_event_notifications": {
     "someone": "Birisi",
     "invited": "{name} sizi \"{title}\" etkinliğine davet etti",
diff --git a/locales/uk/common.json b/locales/uk/common.json
index b0d90b0f8..0b2dc73fe 100644
--- a/locales/uk/common.json
+++ b/locales/uk/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "Ви відхилили.",
     "answered_tentative_nodate": "Ви відповіли «можливо»."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Повторюється: {rule}",
+    "declined_dates": "Ви відхилили зустріч {dates}.",
+    "declined_many": "Ви відхилили зустрічей цієї серії: {count}.",
+    "answers_series": "Ваша відповідь стосується всіх зустрічей серії."
+  },
   "advanced_search": {
     "title": "Розширений пошук",
     "from": "Від",
diff --git a/locales/vi/common.json b/locales/vi/common.json
index 367c03dd8..89d844cd4 100644
--- a/locales/vi/common.json
+++ b/locales/vi/common.json
@@ -5238,6 +5238,12 @@
     "answered_declined_nodate": "Bạn đã từ chối.",
     "answered_tentative_nodate": "Bạn đã trả lời có thể."
   },
+  "ux_p2_pim_calx": {
+    "repeats": "Lặp lại: {rule}",
+    "declined_dates": "Bạn đã từ chối ngày {dates}.",
+    "declined_many": "Bạn đã từ chối {count} cuộc họp trong chuỗi này.",
+    "answers_series": "Câu trả lời của bạn áp dụng cho mọi cuộc họp trong chuỗi."
+  },
   "calendar_event_notifications": {
     "someone": "Ai đó",
     "invited": "{name} đã mời bạn tham gia \"{title}\"",
diff --git a/locales/zh-TW/common.json b/locales/zh-TW/common.json
index 0b3d88f49..254ba30ee 100644
--- a/locales/zh-TW/common.json
+++ b/locales/zh-TW/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "你已拒絕。",
     "answered_tentative_nodate": "你已回覆暫定。"
   },
+  "ux_p2_pim_calx": {
+    "repeats": "重複：{rule}",
+    "declined_dates": "您已拒絕 {dates} 的會議。",
+    "declined_many": "您已拒絕此系列中的 {count} 場會議。",
+    "answers_series": "您的回覆適用於此系列的所有會議。"
+  },
   "calendar_event_notifications": {
     "someone": "有人",
     "invited": "{name} 邀請您參加「{title}」",
diff --git a/locales/zh/common.json b/locales/zh/common.json
index 7ac44e08e..1f9dbdb79 100644
--- a/locales/zh/common.json
+++ b/locales/zh/common.json
@@ -5226,6 +5226,12 @@
     "answered_declined_nodate": "你已拒绝。",
     "answered_tentative_nodate": "你已答复暂定。"
   },
+  "ux_p2_pim_calx": {
+    "repeats": "重复：{rule}",
+    "declined_dates": "您已拒绝 {dates} 的会议。",
+    "declined_many": "您已拒绝此系列中的 {count} 次会议。",
+    "answers_series": "您的回复适用于此系列的所有会议。"
+  },
   "advanced_search": {
     "title": "高级搜索",
     "from": "发件人",