The abbreviations a.m. and p.m. are generally lowercased in running text, but they may also be capitalized (for example, in headings, signs, and notices). ... Also, if you do capitalize these abbreviations in a document, consider using small caps to improve readability (8:30 AM ).

What is the correct way to write AM and PM?

The first and most common way to write them is with lowercase “a.m.” and “p.m.” This way requires periods, and both Chicago Style and AP Style recommend this way of writing the abbreviations. This subway train will leave daily at 10:05 a.m. After 10:00 p.m. I really need to sleep.

Is it 2pm or 2 pm?

In addition, when writing the times 1:00 pm, 2:00 pm, etc., it is perfectly acceptable to omit the zeroes and write 1 pm, 2 pm, instead. Finally, note that while in the US we use a 12-hour clock, some countries use a 24-hour clock, or military time.