Usually, in most of the areas, you do not need to write down the exact time. But there comes some important occasions, for which, you have to specify the time of day.
What AP Style Time Suggests?
1. In the areas where you have to mention the time of day, you should use figures for that. If you are referring noon or midnight then, you have to spell out the whole word (i.e. noon or midnight).
2. You should not capitalize the abbreviations a.m. (for ante meridiem) and p.m. ( for post meridiem).
• The event will be held at 10 a.m.
3. You should avoid using unnecessary zeroes. Like,
10:00 p.m. (Wrong)
10 p.m. (Correct)
4. Use a.m. or p.m. only once within a sentence. For instance, “7:45 – 10 a.m.”
5. If the time goes from morning into the evening or from the evening into the morning, you should mention both a.m. and p.m. For instance, “7 a.m. – 2:30 p.m.”
6. You have noticed that you should use a colon to separate hours from minutes. Like, 7:45 a.m.
7. If you are referring the units of measurement in time sequences the. You should spell out the whole words i.e. “2 hours, 10 minutes, 20 seconds.”