refactor(roadtrip): read the wall clock minutes and today through localDate

useMRoadtrip and useMRtCorridor each kept a nowMinutes helper and their
own check whether the selected day is today. Both now use localMinutes
and isLocalToday from utils/localDate.ts, which hold the same rules.

client/src/mobile/screens/trip/roadtrip/useMRoadtrip.ts

@@ -8,13 +8,7 @@ import type { RoadtripDay } from '@trek/shared/roadtrip'
 import type { MTripShellApi, TripPlanner } from '../MTripShell'
 import type { RoadtripRow, StopRow } from '../../../../components/Roadtrip/roadtripRowModel'
 import type { Category, Place } from '../../../../types'
-import { localIsoDate } from '../../../../utils/localDate'
-
-/** Minutes since midnight, local time. */
-const nowMinutes = (): number => {
-  const d = new Date()
-  return d.getHours() * 60 + d.getMinutes()
-}
+import { isLocalToday, localMinutes } from '../../../../utils/localDate'
 
 /** The same 30 s tick the day timeline runs on, so the two never disagree by a minute. */
 const TICK_MS = 30_000
@@ -52,11 +46,11 @@ export interface MRoadtripController {
 export function useMRoadtrip(planner: TripPlanner): MRoadtripController {
   const { roadtripRoutes, selectedDayId, days } = planner
   const vehicle = useRoadtripSettings(s => s.roadtrip_vehicle, planner.tripId)
-  const [minutes, setMinutes] = useState(nowMinutes)
+  const [minutes, setMinutes] = useState(localMinutes)
   const [offline, setOffline] = useState(isEffectivelyOffline)
 
   useEffect(() => {
-    const id = window.setInterval(() => setMinutes(nowMinutes()), TICK_MS)
+    const id = window.setInterval(() => setMinutes(localMinutes()), TICK_MS)
     return () => window.clearInterval(id)
   }, [])
 
@@ -88,14 +82,13 @@ export function useMRoadtrip(planner: TripPlanner): MRoadtripController {
 
   // "Today" is the stage's own date, not the selected day's index: a trip can be
   // planned for next year, and a countdown on a day in March is noise.
-  const isToday = useMemo(() => {
-    const date = days.find(d => d.id === selectedDayId)?.date
-    if (!date) return false
-    // The wall clock, not UTC: `nowMinutes` above is local, and between local midnight
-    // and the UTC rollover the two disagree, so east of Greenwich the card hung on
-    // yesterday's stage for the first hours of every night. `localDate.ts` says as much.
-    return date.slice(0, 10) === localIsoDate()
-  }, [days, selectedDayId])
+  // The wall clock, not UTC: the minutes above are local, and between local midnight
+  // and the UTC rollover the two disagree, so east of Greenwich the card hung on
+  // yesterday's stage for the first hours of every night. `localDate.ts` says as much.
+  const isToday = useMemo(
+    () => isLocalToday(days.find(d => d.id === selectedDayId)?.date),
+    [days, selectedDayId],
+  )
 
   return {
     stage,

client/src/mobile/screens/trip/roadtrip/useMRtCorridor.ts

@@ -4,13 +4,7 @@ import { stageOf, upNextStop } from '../../../../components/Roadtrip/roadtripRow
 import { useNetworkMode } from '../../../../hooks/useNetworkMode'
 import type { CorridorPoi } from '../../../../components/Roadtrip/useCorridorPois'
 import type { MTripShellApi, TripPlanner } from '../MTripShell'
-import { localIsoDate } from '../../../../utils/localDate'
-
-/** Minutes since midnight, local time: the same reading the stage screen takes. */
-const nowMinutes = (): number => {
-  const d = new Date()
-  return d.getHours() * 60 + d.getMinutes()
-}
+import { isLocalToday, localMinutes } from '../../../../utils/localDate'
 
 export interface MRtCorridorController {
   /** What is being looked for. Several at once: they ride one query per box. */
@@ -94,8 +88,8 @@ export function useMRtCorridor(planner: TripPlanner, shell: MTripShellApi): MRtC
     const date = planner.days.find(d => d.id === planner.selectedDayId)?.date
     // Local, for the reason useMRoadtrip gives: the clock this is compared against is the
     // wall clock, and UTC disagrees with it for the first hours of every night.
-    const isToday = !!date && date.slice(0, 10) === localIsoDate()
-    const next = upNextStop(stage, nowMinutes(), isToday)
+    const isToday = isLocalToday(date)
+    const next = upNextStop(stage, localMinutes(), isToday)
     if (!next) return -1
     return stage.stops.findIndex(s => s.assignmentId === next.row.stop.assignmentId)
   }, [stage, planner.days, planner.selectedDayId])

client/src/utils/localDate.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest'
-import { localIsoDate } from './localDate'
+import { isLocalToday, localIsoDate, localMinutes } from './localDate'
 
 /**
  * "Today" must be the user's local calendar date. `toISOString()` is the UTC
@@ -26,3 +26,43 @@ describe('localIsoDate', () => {
     expect(localIsoDate()).toBe(localIsoDate(new Date()))
   })
 })
+
+describe('localMinutes', () => {
+  afterEach(() => {
+    vi.useRealTimers()
+  })
+
+  it('counts the minutes since local midnight', () => {
+    expect(localMinutes(new Date(2026, 7, 25, 0, 0))).toBe(0)
+    expect(localMinutes(new Date(2026, 7, 25, 13, 45, 59))).toBe(825)
+    expect(localMinutes(new Date(2026, 7, 25, 23, 59))).toBe(1439)
+  })
+
+  it('defaults to now', () => {
+    vi.useFakeTimers()
+    vi.setSystemTime(new Date(2026, 7, 25, 0, 30))
+    expect(localMinutes()).toBe(30)
+  })
+})
+
+describe('isLocalToday', () => {
+  beforeEach(() => {
+    vi.useFakeTimers()
+    vi.setSystemTime(new Date(2026, 7, 25, 0, 30)) // local 2026-08-25 00:30
+  })
+  afterEach(() => {
+    vi.useRealTimers()
+  })
+
+  it('matches the local calendar date, with or without a time part', () => {
+    expect(isLocalToday('2026-08-25')).toBe(true)
+    expect(isLocalToday('2026-08-25T00:00:00.000Z')).toBe(true)
+  })
+
+  it('is false for another date or no date at all', () => {
+    expect(isLocalToday('2026-08-24')).toBe(false)
+    expect(isLocalToday('')).toBe(false)
+    expect(isLocalToday(null)).toBe(false)
+    expect(isLocalToday(undefined)).toBe(false)
+  })
+})

client/src/utils/localDate.ts

@@ -14,3 +14,16 @@
 export function localIsoDate(d: Date = new Date()): string {
   return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`
 }
+
+/** Minutes since local midnight: the wall clock a day's schedule is read against. */
+export function localMinutes(d: Date = new Date()): number {
+  return d.getHours() * 60 + d.getMinutes()
+}
+
+/**
+ * Whether a trip day's date (anything starting 'YYYY-MM-DD') is today on the wall
+ * clock. Local for the reason `localIsoDate` gives; a day without a date is never today.
+ */
+export function isLocalToday(date: string | null | undefined): boolean {
+  return !!date && date.slice(0, 10) === localIsoDate()
+}