So we wan't to know how much time has passed from 2:16 AM till 8:10 PM. If we know that one day has 24 hours and that AM and PM are two 12 hour periods we can say the following: 2:16 AM is 2:16 h in the 24 hour cycle. and 8:10 PM is 20:10 h in the 24 hour cycle. so from 2:16 hours to 20:10 hours there is a time interval of 17 hours and 54 minutes.