You do not have to reactivate the alarm every day manually. The alarm can be activated or deactivated using the ALARM ON/OFF slider; once activated, it will sound at the set time daily until you slide the switch off. The snooze function can be used to temporarily silence the alarm, which will then sound again after 5 minutes, but the alarm itself remains active until you turn it off with the slider.
The answer from Galaxus is wrong. You do not have to set the alarm time every day. However, you must actively set the alarm every day, as you have to switch off the alarm in the morning by deactivating it.