Default What is com.android.server$alarmManager ?

This process seems to be complained about by MIUI users and there doesn't seem to be a clear explanation of what it does. The main annoyance about it is that it repeatedly wakes up the phone while it's trying to sleep. I am trying to figure out if this is normal or if it is some sort of bug. When I look at my battery logs it shows this process as eating up a significant amount of battery. Can somebody please help?