Four hours exactly.
From 2pm to 6pm is 4 hours. From 2am to 6pm is 16 hours.
If it's 6pm - the time 20 hours later will be 2pm the following day. For example if it's 6pm on Tue Oct 19th... 20 hours later it'll be 2pm on Wed Oct 20th
3am to 2pm is 11 hours.
10 hours
There are 7 hours between 7 am to 2pm
3am to 2pm is 11 hours.
7am to 2pm is 7 hour.
24 hours
48 hours.
There are 17 hours between 9pm and 2pm the following day.
Mon 8-2pm tues-fri 8-6pm and sat 7-4pm