It is 24 hours.8am to 8pm = 12 hours.8pm to 8am = 12 hours.2 x 12 = 24.
12 noon in 24-hour time is 12:00.
In 24-hour time, it's "1500 hours". In 12-hour time, it's "3:00 PM".
If it is 12 hours and has a pm, add 12. If it is 24 hours and you can take 12 away, do and put pm after it. If you cannot, call it am.
Add 12 hours to it: 20:30
On average about 12 hours, but it can be anywhere from 0 to 24 hours, depending on your latitude and the time of the year.
There are 12 hours as am and 12 hours as pm. This in total makes 24 hours a day. for 24 hour time, from 12 midnight to 12 noon it is am. Then pm hours start from 12 noon to just before 12 midnight. The change from am to pm is in one moment.
There are 12 hours between 12 pm and 12 am. The PM period lasts the same as the AM period, 12 hours.
12:00 hours
5/12 of 24 = 24*5/12 = 10 hours
12 to 24 hours
Probably because people will get confused if they tried to use military time (which is based on the 24 hours clock. 2000 hrs is 8pm, 12+8=20).