diff --git a/client/src/components/PDF/TripPDF.tsx b/client/src/components/PDF/TripPDF.tsx
index 1a5a3316..e5700b93 100644
--- a/client/src/components/PDF/TripPDF.tsx
+++ b/client/src/components/PDF/TripPDF.tsx
@@ -4,6 +4,7 @@ import { getCategoryIcon } from '../shared/categoryIcons'
 import { FileText, Info, Clock, MapPin, Navigation, Train, Plane, Bus, Car, Ship, Coffee, Ticket, Star, Heart, Camera, Flag, Lightbulb, AlertTriangle, ShoppingBag, Bookmark, Hotel, LogIn, LogOut, KeyRound, BedDouble, Utensils, Users, LucideIcon } from 'lucide-react'
 import { accommodationsApi, mapsApi } from '../../api/client'
 import type { Trip, Day, Place, Category, AssignmentsMap, DayNotesMap } from '../../types'
+import { isDayInAccommodationRange, getDayOrder } from '../../utils/dayOrder'
 
 function renderLucideIcon(icon:LucideIcon, props = {}) {
   if (!_renderToStaticMarkup) return ''
@@ -285,8 +286,12 @@ export async function downloadTripPDF({ trip, days, places, assignments, categor
       }).join('')
 
     const accommodationsForDay = (accommodations.accommodations || []).filter(a =>
-      days.some(d => d.id >= a.start_day_id && d.id <= a.end_day_id && d.id === day?.id)
-    ).sort((a, b) => a.start_day_id - b.start_day_id)
+      day ? isDayInAccommodationRange(day, a.start_day_id, a.end_day_id, days) : false
+    ).sort((a, b) => {
+      const startA = days.find(d => d.id === a.start_day_id)
+      const startB = days.find(d => d.id === b.start_day_id)
+      return (startA ? getDayOrder(startA, days) : 0) - (startB ? getDayOrder(startB, days) : 0)
+    })
 
     const accommodationDetails = accommodationsForDay.map(item => {
       const isCheckIn = day.id === item.start_day_id
diff --git a/client/src/components/Planner/DayDetailPanel.test.tsx b/client/src/components/Planner/DayDetailPanel.test.tsx
index 9bdc0256..a70fd9d5 100644
--- a/client/src/components/Planner/DayDetailPanel.test.tsx
+++ b/client/src/components/Planner/DayDetailPanel.test.tsx
@@ -1069,6 +1069,100 @@ describe('DayDetailPanel', () => {
     });
   });
 
+  // ── Post-save state filter — non-monotonic IDs (issue #889 follow-up) ────────
+
+  it('FE-PLANNER-DAYDETAIL-060: non-monotonic IDs — hotel stays visible after edit-save (issue #889 regression)', async () => {
+    const days = buildNonMonotonicDays();
+    let getCallCount = 0;
+    server.use(
+      http.get('/api/trips/1/accommodations', () => {
+        getCallCount++;
+        const acc = getCallCount === 1
+          // Initial load: single-day so old filter (17>=17 && 17<=17) passes — hotel visible, edit possible
+          ? { id: 1, place_id: 50, place_name: 'Span Hotel', place_address: null, start_day_id: 17, end_day_id: 17, check_in: null, check_out: null, confirmation: null }
+          // Post-save relist: full span — old filter (17>=17 && 17<=7) would drop it, new code keeps it
+          : { id: 1, place_id: 50, place_name: 'Span Hotel', place_address: null, start_day_id: 17, end_day_id: 7, check_in: null, check_out: null, confirmation: null };
+        return HttpResponse.json({ accommodations: [acc] });
+      }),
+      http.put('/api/trips/1/accommodations/1', async ({ request }) => {
+        const body = await request.json() as any;
+        return HttpResponse.json({
+          accommodation: { id: 1, place_id: 50, place_name: 'Span Hotel', place_address: null,
+            start_day_id: body.start_day_id, end_day_id: body.end_day_id,
+            check_in: null, check_out: null, confirmation: null },
+        });
+      }),
+    );
+
+    render(<DayDetailPanel {...defaultProps} day={days[0]} days={days} />);
+    await screen.findByText('Span Hotel');
+
+    // Pencil = 3rd button (index 2): collapse, close, pencil, remove
+    const allButtons = screen.getAllByRole('button');
+    await userEvent.click(allButtons[2]);
+
+    // Extend end picker to Day 16 (id=7)
+    await userEvent.click(getDayPickerTriggers()[1]);
+    await userEvent.click(screen.getAllByRole('button').find(b => b.textContent?.startsWith('Day 16'))!);
+    await userEvent.click(screen.getByRole('button', { name: /^Save$/i }));
+
+    // Old code: 17>=17 && 17<=7 → false (hotel vanishes). New code: position 0 in [0,15] → visible.
+    await waitFor(() => {
+      expect(screen.getByText('Span Hotel')).toBeInTheDocument();
+    });
+  });
+
+  it('FE-PLANNER-DAYDETAIL-061: non-monotonic IDs — hotel appears after create-save on intermediate day', async () => {
+    const days = buildNonMonotonicDays();
+    const place = buildPlace({ id: 55, name: 'Created Hotel' });
+    // Current day: days[5] = id 22, position 5 (within any full-span range)
+    const currentDay = days[5];
+    server.use(
+      http.post('/api/trips/1/accommodations', async ({ request }) => {
+        const body = await request.json() as any;
+        return HttpResponse.json({
+          accommodation: { id: 200, place_id: 55, place_name: 'Created Hotel', place_address: null,
+            start_day_id: body.start_day_id, end_day_id: body.end_day_id,
+            check_in: null, check_out: null, confirmation: null },
+        });
+      }),
+    );
+
+    render(<DayDetailPanel {...defaultProps} day={currentDay} days={days} places={[place]} />);
+    await userEvent.click(await screen.findByText(/Add accommodation/i));
+    await userEvent.click(await screen.findByRole('button', { name: /Created Hotel/i }));
+
+    // Extend end to Day 16 (id=7) — start stays at current day id=22
+    await userEvent.click(getDayPickerTriggers()[1]);
+    await userEvent.click(screen.getAllByRole('button').find(b => b.textContent?.startsWith('Day 16'))!);
+    await userEvent.click(screen.getByRole('button', { name: /^Save$/i }));
+
+    // Old code: 22>=22 && 22<=7 → false (hotel vanishes). New code: position 5 in [5,15] → visible.
+    await waitFor(() => {
+      expect(screen.getByText('Created Hotel')).toBeInTheDocument();
+    });
+  });
+
+  it('FE-PLANNER-DAYDETAIL-062: non-monotonic IDs — hotel shown on initial load when it spans the full trip', async () => {
+    const days = buildNonMonotonicDays();
+    server.use(
+      http.get('/api/trips/1/accommodations', () =>
+        HttpResponse.json({
+          accommodations: [{ id: 1, place_id: 60, place_name: 'Full Trip Hotel', place_address: null,
+            start_day_id: 17, end_day_id: 7, check_in: null, check_out: null, confirmation: null }],
+        })
+      ),
+    );
+
+    // Day 1 (id=17): old filter: 17>=17 && 17<=7 → false. New: position 0 in [0,15] → visible.
+    render(<DayDetailPanel {...defaultProps} day={days[0]} days={days} />);
+    await screen.findByText('Full Trip Hotel');
+
+    // Intermediate day (id=1, position 9): old filter: 1>=17 → false. New: 9 in [0,15] → visible.
+    render(<DayDetailPanel {...defaultProps} day={days[9]} days={days} />);
+    await screen.findByText('Full Trip Hotel');
+  });
+
   it('FE-PLANNER-DAYDETAIL-040: 12h time format renders reservation time with AM/PM', async () => {
     seedStore(useSettingsStore, {
       settings: { time_format: '12h', temperature_unit: 'celsius', blur_booking_codes: false },
diff --git a/client/src/components/Planner/DayDetailPanel.tsx b/client/src/components/Planner/DayDetailPanel.tsx
index 0d53f8ff..407db408 100644
--- a/client/src/components/Planner/DayDetailPanel.tsx
+++ b/client/src/components/Planner/DayDetailPanel.tsx
@@ -12,6 +12,7 @@ import CustomTimePicker from '../shared/CustomTimePicker'
 import { useSettingsStore } from '../../store/settingsStore'
 import { getLocaleForLanguage, useTranslation } from '../../i18n'
 import type { Day, Place, Category, Reservation, AssignmentsMap } from '../../types'
+import { isDayInAccommodationRange } from '../../utils/dayOrder'
 
 const WEATHER_ICON_MAP = {
   Clear: Sun, Clouds: Cloud, Rain: CloudRain, Drizzle: CloudDrizzle,
@@ -99,7 +100,7 @@ export default function DayDetailPanel({ day, days, places, categories = [], tri
       .then(data => {
         setAccommodations(data.accommodations || [])
         const allForDay = (data.accommodations || []).filter(a =>
-          days.some(d => d.id >= a.start_day_id && d.id <= a.end_day_id && d.id === day?.id)
+          day ? isDayInAccommodationRange(day, a.start_day_id, a.end_day_id, days) : false
         )
         setDayAccommodations(allForDay)
         setAccommodation(allForDay[0] || null)
@@ -130,7 +131,7 @@ export default function DayDetailPanel({ day, days, places, categories = [], tri
       setAccommodations(updated)
       setAccommodation(newAcc)
       setDayAccommodations(updated.filter(a =>
-        days.some(d => d.id >= a.start_day_id && d.id <= a.end_day_id && d.id === day?.id)
+        day ? isDayInAccommodationRange(day, a.start_day_id, a.end_day_id, days) : false
       ))
       setShowHotelPicker(false)
       setHotelForm({ check_in: '', check_in_end: '', check_out: '', confirmation: '', place_id: null })
@@ -154,7 +155,7 @@ export default function DayDetailPanel({ day, days, places, categories = [], tri
       const updated = accommodations.filter(a => a.id !== accommodation.id)
       setAccommodations(updated)
       setDayAccommodations(updated.filter(a =>
-        days.some(d => d.id >= a.start_day_id && d.id <= a.end_day_id && d.id === day?.id)
+        day ? isDayInAccommodationRange(day, a.start_day_id, a.end_day_id, days) : false
       ))
       setAccommodation(null)
       onAccommodationChange?.()
@@ -598,9 +599,9 @@ export default function DayDetailPanel({ day, days, places, categories = [], tri
                         const all = d.accommodations || []
                         setAccommodations(all)
                         setDayAccommodations(all.filter(a =>
-                          days.some(dd => dd.id >= a.start_day_id && dd.id <= a.end_day_id && dd.id === day?.id)
+                          day ? isDayInAccommodationRange(day, a.start_day_id, a.end_day_id, days) : false
                         ))
-                        const acc = all.find(a => days.some(dd => dd.id >= a.start_day_id && dd.id <= a.end_day_id && dd.id === day?.id))
+                        const acc = all.find(a => day ? isDayInAccommodationRange(day, a.start_day_id, a.end_day_id, days) : false)
                         setAccommodation(acc || null)
                       })
                       onAccommodationChange?.()
diff --git a/client/src/components/Planner/DayPlanSidebar.tsx b/client/src/components/Planner/DayPlanSidebar.tsx
index b1eda2d3..7c44f091 100644
--- a/client/src/components/Planner/DayPlanSidebar.tsx
+++ b/client/src/components/Planner/DayPlanSidebar.tsx
@@ -21,6 +21,7 @@ import { useTripStore } from '../../store/tripStore'
 import { useCanDo } from '../../store/permissionsStore'
 import { useSettingsStore } from '../../store/settingsStore'
 import { useTranslation } from '../../i18n'
+import { isDayInAccommodationRange } from '../../utils/dayOrder'
 import { formatDate, formatTime, dayTotalCost, currencyDecimals } from '../../utils/formatters'
 import { useDayNotes } from '../../hooks/useDayNotes'
 import Tooltip from '../shared/Tooltip'
@@ -1214,7 +1215,7 @@ const DayPlanSidebar = React.memo(function DayPlanSidebar({
                         </Tooltip>
                       )}
                       {(() => {
-                        const dayAccs = accommodations.filter(a => day.id >= a.start_day_id && day.id <= a.end_day_id)
+                        const dayAccs = accommodations.filter(a => isDayInAccommodationRange(day, a.start_day_id, a.end_day_id, days))
                           // Sort: check-out first, then ongoing stays, then check-in last
                           .sort((a, b) => {
                             const aIsOut = a.end_day_id === day.id && a.start_day_id !== day.id
diff --git a/client/src/pages/SharedTripPage.tsx b/client/src/pages/SharedTripPage.tsx
index 09fa8669..e7c75c1f 100644
--- a/client/src/pages/SharedTripPage.tsx
+++ b/client/src/pages/SharedTripPage.tsx
@@ -10,6 +10,7 @@ import { getCategoryIcon } from '../components/shared/categoryIcons'
 import { createElement } from 'react'
 import { renderToStaticMarkup } from 'react-dom/server'
 import { Clock, MapPin, FileText, Train, Plane, Bus, Car, Ship, Ticket, Hotel, Map, Luggage, Wallet, MessageCircle } from 'lucide-react'
+import { isDayInAccommodationRange } from '../utils/dayOrder'
 
 const TRANSPORT_TYPES = new Set(['flight', 'train', 'bus', 'car', 'cruise'])
 const TRANSPORT_ICONS = { flight: Plane, train: Train, bus: Bus, car: Car, cruise: Ship }
@@ -184,7 +185,7 @@ export default function SharedTripPage() {
             const da = assignments[String(day.id)] || []
             const notes = (dayNotes[String(day.id)] || [])
             const dayTransport = (reservations || []).filter((r: any) => TRANSPORT_TYPES.has(r.type) && r.reservation_time?.split('T')[0] === day.date)
-            const dayAccs = (accommodations || []).filter((a: any) => day.id >= a.start_day_id && day.id <= a.end_day_id)
+            const dayAccs = (accommodations || []).filter((a: any) => isDayInAccommodationRange(day, a.start_day_id, a.end_day_id, sortedDays))
 
             const merged = [
               ...da.map((a: any) => ({ type: 'place', k: a.order_index, data: a })),
diff --git a/client/src/types.ts b/client/src/types.ts
index 5701597a..8c9c3039 100644
--- a/client/src/types.ts
+++ b/client/src/types.ts
@@ -31,6 +31,7 @@ export interface Trip {
 export interface Day {
   id: number
   trip_id: number
+  day_number?: number
   date: string
   title: string | null
   notes: string | null
diff --git a/client/src/utils/dayOrder.ts b/client/src/utils/dayOrder.ts
new file mode 100644
index 00000000..8ef66046
--- /dev/null
+++ b/client/src/utils/dayOrder.ts
@@ -0,0 +1,23 @@
+import type { Day } from '../types'
+
+export const getDayOrder = (day: Day, days: Day[]): number =>
+  day.day_number ?? days.indexOf(day)
+
+export const isDayInAccommodationRange = (
+  day: Day,
+  startDayId: number,
+  endDayId: number,
+  days: Day[],
+): boolean => {
+  const startDay = days.find(d => d.id === startDayId)
+  const endDay = days.find(d => d.id === endDayId)
+  if (!startDay || !endDay) {
+    // Endpoint days not in the loaded array (e.g. sparse test data or partial load).
+    // Fall back to numeric ID range — acceptable since non-monotonic IDs only arise when
+    // both endpoints are present in a fully-loaded trip's days list.
+    return day.id >= Math.min(startDayId, endDayId) && day.id <= Math.max(startDayId, endDayId)
+  }
+  const lo = Math.min(getDayOrder(startDay, days), getDayOrder(endDay, days))
+  const hi = Math.max(getDayOrder(startDay, days), getDayOrder(endDay, days))
+  return getDayOrder(day, days) >= lo && getDayOrder(day, days) <= hi
+}