How to set Alarms on the DS3231 easily so the Nano doesn't have to go to sleep with delay statements? I want my solar array sun tracker to shut down at night then move full east in the morning to catch the first rays.  

I know the DS3231 can set alarms but it is not clear from its documentation how to do it with the normal library.  

Delay statements are the way I have it periodically check for when to take readings, but I really want it to be able to respond to radio-remote control commands, which don't work during delays.

Q:  Is there an easier way?
Here it is:

https://github.com/sleemanj/DS3231_Simple

Example:  https://github.com/sleemanj/DS3231_Simple/blob/master/examples/z2_Alarms/Alarm/Alarm.ino

This is what I was looking for.  

My system needs to be able to respond to radio remote commands while asleep, and the long delay() statements were preventing that.  

These alarms solve the problem.