feat(boss-dashboard): add windowRange helper with UTC boundaries

src/lib/server/boss-dashboard-service.test.ts

@@ -0,0 +1,30 @@
+import { describe, it, expect } from "vitest";
+import { windowRange } from "./boss-dashboard-service";
+
+describe("windowRange", () => {
+  it("today: start of UTC day to start of next UTC day", () => {
+    const r = windowRange("today", new Date("2026-08-27T14:32:11.000Z"));
+    expect(r.rangeStart).toBe("2026-08-27T00:00:00.000Z");
+    expect(r.rangeEnd).toBe("2026-08-28T00:00:00.000Z");
+  });
+
+  it("week: Monday 00:00 UTC to next Monday 00:00 UTC", () => {
+    // 2026-08-27 is a Thursday. Week starts Mon 2026-08-24.
+    const r = windowRange("week", new Date("2026-08-27T14:32:11.000Z"));
+    expect(r.rangeStart).toBe("2026-08-24T00:00:00.000Z");
+    expect(r.rangeEnd).toBe("2026-08-31T00:00:00.000Z");
+  });
+
+  it("month: first of month to first of next month", () => {
+    const r = windowRange("month", new Date("2026-08-27T14:32:11.000Z"));
+    expect(r.rangeStart).toBe("2026-08-01T00:00:00.000Z");
+    expect(r.rangeEnd).toBe("2026-09-01T00:00:00.000Z");
+  });
+
+  it("week across month boundary: still anchored to Monday", () => {
+    // 2026-09-02 is a Wednesday. Week starts Mon 2026-08-31, ends Mon 2026-09-07.
+    const r = windowRange("week", new Date("2026-09-02T09:00:00.000Z"));
+    expect(r.rangeStart).toBe("2026-08-31T00:00:00.000Z");
+    expect(r.rangeEnd).toBe("2026-09-07T00:00:00.000Z");
+  });
+});

src/lib/server/boss-dashboard-service.ts

@@ -0,0 +1,47 @@
+export type BossWindow = "today" | "week" | "month";
+
+export interface WindowRange {
+  rangeStart: string; // ISO
+  rangeEnd: string;   // ISO
+}
+
+/**
+ * Computes the [start, end) UTC window for a boss-dashboard time tab.
+ * Today: midnight-to-midnight UTC.
+ * Week: Monday 00:00 UTC to next Monday 00:00 UTC.
+ * Month: day-1 00:00 UTC to day-1 of next month.
+ *
+ * All UTC because that's how PocketBase `created` timestamps compare.
+ */
+export function windowRange(window: BossWindow, now: Date = new Date()): WindowRange {
+  const start = new Date(now);
+  const end = new Date(now);
+
+  switch (window) {
+    case "today": {
+      start.setUTCHours(0, 0, 0, 0);
+      end.setUTCDate(end.getUTCDate() + 1);
+      end.setUTCHours(0, 0, 0, 0);
+      break;
+    }
+    case "week": {
+      // Monday = 1, Sunday = 0. Shift so Monday is start.
+      const day = start.getUTCDay();
+      const diffToMonday = day === 0 ? -6 : 1 - day;
+      start.setUTCDate(start.getUTCDate() + diffToMonday);
+      start.setUTCHours(0, 0, 0, 0);
+      end.setTime(start.getTime());
+      end.setUTCDate(end.getUTCDate() + 7);
+      break;
+    }
+    case "month": {
+      start.setUTCDate(1);
+      start.setUTCHours(0, 0, 0, 0);
+      end.setUTCMonth(end.getUTCMonth() + 1, 1);
+      end.setUTCHours(0, 0, 0, 0);
+      break;
+    }
+  }
+
+  return { rangeStart: start.toISOString(), rangeEnd: end.toISOString() };
+}