https://github.com/firebase/extensions/blob/f59076ff5461f4426a960219d7df21a937893ec1/firestore-send-email/functions/src/index.ts#L117 It seems like the TTL type "day" and "week" seems to evaluate the same expire date: case "day": now.setDate(now.getDate() + value); break; case "week": now.setDate(now.getDate() + value); break; I guess "week" should be now.getDate() + 7 * value