web: fix ✨ timezone issues ✨ so midnight ISR happens the right day

2026-09-04 21:28:17 +02:00
parent b7ff7a3ddc
commit a678adc9d3
7 changed files with 72 additions and 13 deletions
@@ -161,4 +161,23 @@ describe("getTodaysOpeningHoursForFunction", () => {
    vi.setSystemTime(new Date("2026-07-07T10:00:00Z"));
    expect(getTodaysOpeningHoursForFunction(openingHours, "kafé")).toBe("?");
  });
+
+  it("uses the Oslo weekday when the server runs in UTC", () => {
+    const tz = process.env.TZ;
+    process.env.TZ = "UTC";
+    try {
+      // 22:20 UTC on torsdag is 00:20 fredag in Oslo (CEST)
+      vi.setSystemTime(new Date("2026-07-09T22:20:00Z"));
+      expect(getTodaysOpeningHoursForFunction(openingHours, "bar")).toBe(
+        "15:00—01:00"
+      );
+      // 23:20 UTC on torsdag is 00:20 fredag in Oslo (CET)
+      vi.setSystemTime(new Date("2026-01-08T23:20:00Z"));
+      expect(getTodaysOpeningHoursForFunction(openingHours, "bar")).toBe(
+        "15:00—01:00"
+      );
+    } finally {
+      process.env.TZ = tz;
+    }
+  });
 });