No such time as 12 am !!!! Do you mean 12 midnight or 12 noon??? 'am' are the Latin initials for 'Ante Meridian' ; Before Noon. If it is midnight or noon it is NOT before or after noon. To answer your question, assuming you mean '12 midnight', then . from 5 pm to 12 midnight it is 7 hours. NB If you mean 12 noon then from 5 pm to the following 12 noon , it is 19 hours.
113 hours
5 hours + 12 hours is 17 hours
12am to 4pm is 16 hours.
24
48 hours.
72 hours
From 6am to 5pm is 11 hours.
Eight hours !
12 hours
18 hours
21