IF they are on the same day, then the interval is 6 hours.
8
All of them. 3PM is 24 hours later than 3PM. However, without a frame of reference (a date) all of them could also be regarded as being earlier than 3PM. That is, 9PM last night would be earlier than 3PM today.
3pm EST is 9pm CET. Central European Time (CET) is 6 hours ahead of Eastern Standard Time (EST).
9am-3pm, 9pm-3am. The other hours is low tide.
3pm to 10pm is 7 hours.
24 hours
13
12 hours.
4to 9pm is how much hours
3 hours between 12pm and 3pm
Between 10am and 9pm, there are 11 hours.
24 of course !
There are 17 hours between 9pm and 2pm the following day.