The RTC is connected to a Watchdog reset circuit which permits to reset the microcontroller of Waspmote when the Alarm2 is triggered. This can be useful in order to avoid Waspmote to get stuck inside an infinite loop. The RTC watchdog can be programmed for several minutes and can be enabled/disabled when required. For instance, it should be restarted in every new loop. Thus, the Waspmote will reset in the case it gets blocked after the programmed alarm expires.
Please refer to the RTC programming guide for more information.