fix: local-time timestamps include offset (#14771) (thanks @0xRaini)

src/cli/logs-cli.ts

@@ -72,11 +72,25 @@ export function formatLogTimestamp(
   if (Number.isNaN(parsed.getTime())) {
     return value;
   }
+
+  const formatLocalIsoWithOffset = (now: Date) => {
+    const year = now.getFullYear();
+    const month = String(now.getMonth() + 1).padStart(2, "0");
+    const day = String(now.getDate()).padStart(2, "0");
+    const h = String(now.getHours()).padStart(2, "0");
+    const m = String(now.getMinutes()).padStart(2, "0");
+    const s = String(now.getSeconds()).padStart(2, "0");
+    const ms = String(now.getMilliseconds()).padStart(3, "0");
+    const tzOffset = now.getTimezoneOffset();
+    const tzSign = tzOffset <= 0 ? "+" : "-";
+    const tzHours = String(Math.floor(Math.abs(tzOffset) / 60)).padStart(2, "0");
+    const tzMinutes = String(Math.abs(tzOffset) % 60).padStart(2, "0");
+    return `${year}-${month}-${day}T${h}:${m}:${s}.${ms}${tzSign}${tzHours}:${tzMinutes}`;
+  };
+
   let timeString: string;
   if (localTime) {
-    const tzoffset = parsed.getTimezoneOffset() * 60000; // offset in milliseconds
-    const localISOTime = new Date(parsed.getTime() - tzoffset).toISOString().slice(0, -1);
-    timeString = localISOTime;
+    timeString = formatLocalIsoWithOffset(parsed);
   } else {
     timeString = parsed.toISOString();
   }