12pm isn't a well defined time, but people usually use it to mean 12 noon, so 7 hours.
(19 +24k) hours where k is an integer.
7
7
Mon - Fri 5am - 12am Sat - 7am - 8pm Sun - 12pm - 6pm
12pm to 7pm is a span of 7 hours.
3 hours between 12pm and 3pm
21
13 hours
Five hours.
9 hours
6 hours
12 hours
6 hours.
20
2