"O" 'clock is an abbreviation of "of the" clock.
Yes, this is okay if you are teaching someone when to say PM/AM. So, if the context is clear, you both know the part of the day, calling it 'o'clock' is common.
The abbreviation am stands for ante-meridiem (before the Sun has crossed the meridian line) and pm stands for post-meridiem (after the Sun has crossed the meridian line).
Why don't people say it's 00:00 o'clock as opposed to saying 12:00 AM? You don't use “o'clock” or am and pm with a 24-hour clock system. So, the times are zero hundred (0000), zero one hundred (0100), zero two hundred (0200), … ten hundred (1000), eleven hundred (1100), twelve hundred… twenty-three hundred (2300).
The word clock (via Medieval Latin clocca from Old Irish clocc, both meaning 'bell'), which gradually supersedes "horologe", suggests that it was the sound of bells which also characterized the prototype mechanical clocks that appeared during the 13th century in Europe.
Diary 1320) Jesus has let us know that in Heaven, the 3 O'Clock hour is a special holy hour, as He said, "it was the hour of grace for the whole world — mercy triumphed over justiceIn this hour, you can obtain everything for yourself and for others for the askingIn this hour, I will refuse nothing to the soul
0. Yes; directly forward is 12:00 (o'clock) and directly behind you is 6:00, with each hour of a clock being thirty degrees left or right of the preceding number (i.e. 1:00 means 30 degrees to your right, 2:00 means 60, 11:00 is 330 degrees to your right or 30 degrees to your left)
1:00 p.m. — 1300 hrs. 2:00 p.m. — 1400 hrs. 3:00 p.m. — 1500 hrs. 4:00 p.m. — 1600 hrs.
Easy to Read Military Time Chart
| 12-hour am-pm clock | 24-hour military time |
|---|
| 8:00 am | 08:00 |
| 9:00 am | 09:00 |
| 10:00 am | 10:00 |
| 11:00 am | 11:00 |
Find the middle point of the angle between your hour hand and the 12 o'clock mark on your watch. Before noon, you'll have to measure clockwise from your hour hand to the 12 o'clock marking, while afternoon, you'll have to measure counterclockwise from your hour hand to the 12 o'clock marking.
Meaning: Watching your back. Military members commonly describe direction using the hours of a clock. Whichever direction the vehicle, unit, or individual is moving is the 12 o'clock position, so the six o'clock position is to the rear.
"When the sun is highest overhead and the shadow goes straight up to the top of the sundial, that's noon. Since the highest point of the day was noon, the opposite has to be midnight that was when the 12 started over again, so that's why the day starts at midnight.
An apostrophe is used in o'clock because the word is a contraction of the phrase "of the clock." Just like other contractions, the apostrophe takes the place of missing words or letters from a longer word or phrase. Always use the shortened form, "o'clock."
How Do You Spell O'CLOCK? Correct spelling for the English word "o'clock" is [?klˈ?k], [?klˈ?k], [?_k_l_ˈ?_k] (IPA phonetic alphabet).