LunaR has 2 kinds of alarms: Bedtime Alarm and Normal Alarm. To set a Bedtime Alarm, you should set an inactivity goal in App--"settings"--"goals" first, so the goals can be showing in alarms under "Hours of Sleep", and you only need to move the circle to set the sleeping time. This is also the data source for sleep monitoring. 

To set a Normal Alarm, you only need to choose the time, and whether to repeat it.