chore: import upstream snapshot with attribution

apps/sim/app/workspace/[workspaceId]/scheduled-tasks/search-params.ts

@@ -0,0 +1,61 @@
+import { createParser, parseAsStringLiteral } from 'nuqs/server'
+
+const CALENDAR_SCOPES = ['day', 'week', 'month'] as const
+
+/** Default calendar granularity; matches the prior `useState` initial scope. */
+export const DEFAULT_CALENDAR_SCOPE = 'week'
+
+const pad2 = (n: number) => String(n).padStart(2, '0')
+
+/**
+ * Local-time date-only parser (`yyyy-MM-dd`).
+ *
+ * Unlike nuqs's built-in `parseAsIsoDate` — which serializes via `toISOString()`
+ * and parses to **UTC** midnight — this reads and writes the date using the
+ * browser's **local** calendar fields. The calendar's `anchor` is a local-time
+ * `Date` (`zonedClockDate`) and all the grid math (`date-fns`) is local, so a
+ * UTC-based parser shifts the day by ±1 in any non-UTC timezone on
+ * reload/deep-link/back-forward. This local parser round-trips losslessly against
+ * that local-time math.
+ */
+const parseAsLocalDate = createParser<Date>({
+  parse(value) {
+    const match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(value)
+    if (!match) return null
+    const date = new Date(Number(match[1]), Number(match[2]) - 1, Number(match[3]))
+    return Number.isNaN(date.getTime()) ? null : date
+  },
+  serialize(value) {
+    return `${value.getFullYear()}-${pad2(value.getMonth() + 1)}-${pad2(value.getDate())}`
+  },
+  eq(a, b) {
+    return (
+      a.getFullYear() === b.getFullYear() &&
+      a.getMonth() === b.getMonth() &&
+      a.getDate() === b.getDate()
+    )
+  },
+})
+
+/**
+ * Co-located, typed URL query-param definitions for the scheduled-tasks calendar.
+ *
+ * - `scope` is the calendar granularity (`day` / `week` / `month`).
+ * - `anchor` is the focused day, stored date-only (`yyyy-MM-dd`) via the
+ *   local-time {@link parseAsLocalDate} so it matches the calendar's local-time
+ *   date math (no timezone day-shift). It is intentionally **nullable** (no
+ *   `.withDefault`): the default anchor is "today", which is dynamic and resolved
+ *   per-timezone in the hook (`anchor = param ?? zonedClockDate(now, tz)`). A
+ *   clean URL therefore means "today", and navigating back to today clears the
+ *   param.
+ */
+export const calendarParsers = {
+  scope: parseAsStringLiteral(CALENDAR_SCOPES).withDefault(DEFAULT_CALENDAR_SCOPE),
+  anchor: parseAsLocalDate,
+} as const
+
+/** Calendar view-state: clean URLs, no back-stack churn. */
+export const calendarUrlKeys = {
+  history: 'replace',
+  clearOnDefault: true,
+} as const