YARA-1258

src/helpers/date-jalali.spec.ts

@@ -0,0 +1,17 @@
+import { toJalaliDateAndTime } from "./date-jalali";
+
+describe("toJalaliDateAndTime", () => {
+  it("always formats timestamps in Asia/Tehran regardless of server timezone", () => {
+    expect(toJalaliDateAndTime("2026-08-10T12:30:45.000Z")).toEqual([
+      "1405/05/19",
+      "16:00",
+    ]);
+  });
+
+  it("uses the Tehran calendar day when UTC and Tehran dates differ", () => {
+    expect(toJalaliDateAndTime("2026-08-10T21:30:00.000Z")).toEqual([
+      "1405/05/20",
+      "01:00",
+    ]);
+  });
+});

src/helpers/date-jalali.ts

@@ -1,3 +1,5 @@
+import { IRAN_TIMEZONE } from "./iran-datetime";
+
 /**
  * Converts an ISO date string or Date to Jalali (Persian) date and time.
  * @param input - ISO date string (e.g. 2026-02-08T13:51:20.747+00:00) or Date
@@ -70,6 +72,7 @@ export function jalaliToGregorianDate(
  */
 export function toJalaliDate(d: Date): string {
   const persianDate = d.toLocaleDateString("fa-IR", {
+    timeZone: IRAN_TIMEZONE,
     year: "numeric",
     month: "2-digit",
     day: "2-digit",
@@ -81,9 +84,12 @@ export function toJalaliDate(d: Date): string {
  * Converts a Date to 24h time string (e.g. 13:37).
  */
 export function toJalaliTime(d: Date): string {
-  const hours = d.getHours().toString().padStart(2, "0");
-  const minutes = d.getMinutes().toString().padStart(2, "0");
-  return `${hours}:${minutes}`;
+  return new Intl.DateTimeFormat("en-GB", {
+    timeZone: IRAN_TIMEZONE,
+    hour: "2-digit",
+    minute: "2-digit",
+    hourCycle: "h23",
+  }).format(d);
 }
 
 /**