10:30 am to 11:30 am is 1 hour
11:30 am to 12:30 pm is 2 hours
12:30 pm to 1:30 pm is 3 hours
1:30 pm to 2:30 pm is 4 hours
2:30 pm to 3:30 pm is 5 hours
3:30 pm to 4:30 pm is 6 hours
4:30 pm to 5:30 pm is 7 hours
5:30 pm to 6:30 pm is 8 hours
So, we have 8 hours