Let's try a number line using military time. Nine o'clock AM is 0900, and one o'clock AM is 0100. So, we start at 0900 and count to 0100:
0900-1000-1100-1200-1300-1400-1500-1600-1700-1800-1900-2000-2100-2200-2300-0000-0100
We get 16 hours. Another way you can do this is simple math.
We know that 0100 is an hour after midnight, and 0000 is midnight. So, take 2400 (another way to look at midnight), and subtract 0900:
Simplified it is 24 - 9 = 15 + 1 = 16
9AM to 1AM is sixteen hours.
56 hours
9am to 1am
12 hours.
19 hours
9 hours
17
6
From 8am to 1pm is 5 hours. From 8am to 1am is 17 hours. From 8pm to 1am is 5 hours. From 8pm to 1pm is 17 hours.
21
From 9am to 6:30pm is 9 hours and 30 minutes.
1am to 8am is 7 hours.1am to 8pm is 19 hours.1pm to 8pm is 7 hours.1pm to 8am is 19 hours.
5 Hours