feat: Schedule bookings

app/utils/toronto.ts

@@ -0,0 +1,83 @@
+export const TZ = 'America/Toronto'
+
+/** YYYY-MM-DD for right now in Toronto */
+export function todayToronto(): string {
+  return toDateToronto(new Date())
+}
+
+/** YYYY-MM-DD in Toronto for any Date */
+export function toDateToronto(date: Date): string {
+  return new Intl.DateTimeFormat('en-CA', { timeZone: TZ }).format(date)
+}
+
+/**
+ * Add n calendar days to a YYYY-MM-DD string.
+ * Uses noon UTC so the shift is always exactly 24 h and never crosses
+ * a Toronto DST boundary ambiguously.
+ */
+export function addDays(isoDate: string, n: number): string {
+  const d = new Date(isoDate + 'T12:00:00Z')
+  d.setUTCDate(d.getUTCDate() + n)
+  return d.toISOString().slice(0, 10)
+}
+
+/** HH:MM in Toronto for a UTC ISO string */
+export function fmtTime(utcIso: string): string {
+  return new Date(utcIso).toLocaleTimeString('en-CA', {
+    timeZone: TZ,
+    hour: '2-digit',
+    minute: '2-digit',
+    hour12: false,
+  })
+}
+
+/** "Wednesday, April 20" style label for a YYYY-MM-DD string */
+export function fmtDateLong(isoDate: string): string {
+  return new Date(isoDate + 'T12:00:00Z').toLocaleDateString('en-CA', {
+    timeZone: TZ,
+    weekday: 'long',
+    month: 'long',
+    day: 'numeric',
+  })
+}
+
+/** { weekday: "Wed", short: "Apr 20" } for a YYYY-MM-DD string */
+export function fmtDayHeader(isoDate: string): { weekday: string; short: string } {
+  const d = new Date(isoDate + 'T12:00:00Z')
+  return {
+    weekday: d.toLocaleDateString('en-CA', { timeZone: TZ, weekday: 'short' }),
+    short: d.toLocaleDateString('en-CA', { timeZone: TZ, month: 'short', day: 'numeric' }),
+  }
+}
+
+/**
+ * YYYY-MM-DD of the Monday that starts the ISO week containing isoDate.
+ * Uses the en-CA weekday name to determine day-of-week in Toronto.
+ */
+export function weekMonday(isoDate: string): string {
+  const d = new Date(isoDate + 'T12:00:00Z')
+  const wd = new Intl.DateTimeFormat('en-CA', { timeZone: TZ, weekday: 'short' }).format(d)
+  const offsets: Record<string, number> = { Mon: 0, Tue: 1, Wed: 2, Thu: 3, Fri: 4, Sat: 5, Sun: 6 }
+  const offset = offsets[wd] ?? 0
+  const monday = new Date(d)
+  monday.setUTCDate(d.getUTCDate() - offset)
+  return monday.toISOString().slice(0, 10)
+}
+
+/** All 7 YYYY-MM-DD strings for the ISO week containing isoDate (Mon → Sun) */
+export function weekDates(isoDate: string): string[] {
+  const mon = weekMonday(isoDate)
+  return Array.from({ length: 7 }, (_, i) => addDays(mon, i))
+}
+
+/**
+ * UTC range string pair that safely covers all Toronto-local timestamps
+ * falling within the isoFrom…isoTo date range.
+ * Adds a 1-day buffer on each side so client-side date filtering is authoritative.
+ */
+export function utcRange(isoFrom: string, isoTo: string): { from: string; to: string } {
+  return {
+    from: addDays(isoFrom, -1) + 'T00:00:00Z',
+    to:   addDays(isoTo,   +1) + 'T23:59:59Z',
+  }
+}