How many hours total are between 8am to 3pm? The easiest way is to divide the counting by midday. After that from 8:00 AM to 12:00 PM is 4 hours and from 12:00 PM to 3:00 PM is 3 hours. Now you just need to sum up these two numbers so it means 4:00 + 3:00 is 7 hours and that is answer to your question.Jan 5, 2019