Forum: english.stackexchange.com
Tags: <orthography><time>
Title: Do I spell out a time in an essay?
Question: When I am writing an essay, do I spell out times? How would I write AM or PM?  Example:     11:45 PM   How would I write that?

Answers:
sents: text: The latest edition of the Chicago Manual of Style recommends am and pm , with or without periods.
text: They used to be set in small caps, but that's falling out of favour.
text: You shouldn't use these abbreviations with the words morning, afternoon, evening, night, or o’clock.
text: There is no need to spell out times in an essay, although you might in creative writing or prose.
text: The important thing is to pick a convention, and be consistent.
answer_details: author: english.stackexchange.com/users/1871/ghoppe
score: 9
sents: text: According to an article on About.com : Dates, phone numbers, and time: Usenumbers for dates: My birthday is March 16.
text: He was born on Valentines Day, 1975.
text: And use numbers for phone numbers: The phonenumber for the school is 800-555-6262
text: And use numbers for time if using a.m. or p.m.:
text: The alarm will sound at 7 p.m. I make my bed at 7 a.m. eachmorning.
text: But spell out times whenusing "o'clock" or when the a.m. orp.m.
text: are omitted: The alarm will soundat seven o'clock.
text: I make my bed atseven each morning.
answer_details: author: english.stackexchange.com/users/2019/Moshe
score: 5
sents: text: Several conventions exist to abbreviate ante meridiem and post meridiem - with or without periods and with capital or small letters.
text: 11 am, 11 a.m., 11 AM, 11 A.M.
text: The choice is made based on regional or typographical factors.
answer_details: author: english.stackexchange.com/users/None/
score: 2
sents: text: "[...] departs at 10:48 P.M." is written in William Strunk Jr. and E.B. White's The Elements of Style .
answer_details: author: english.stackexchange.com/users/39802/Jade
score: 1
sents: text: The correct way to write a precise time when using the acronym of Ante or Post Meridiem is AM or PM in professional writing.
text: Sources: Common Errors in English Usage
text: The time stamp on your email, mobile phone, digital clock, Microsoft Windows, etc.
answer_details: author: english.stackexchange.com/users/59788/user59788
score: 1
sents: text: “A quarter of/to/till midnight” or “Eleven forty-five in the evening”
answer_details: author: english.stackexchange.com/users/39/nohat
score: 0

Summary of the answers:
It is generally agreed that the correct way for writing Ante or Post Meridiem in professional writing is with "am" and "pm", with or without periods. This is recommended by the Chicago Manual of Style. However, there is no clear rule as to whether this should be written in capitals or lower case.
The latest edition of the  Chicago Manual of Style  recommends  am  and  pm , with or without periods.They used to be set in small caps, but that's falling out of favour. One shouldn't use these abbreviations with the words morning, afternoon, evening, night, or o’clock. There is no need to spell out times in an essay, although you might in creative writing or prose. Consistency is the key.  Ue numbers for time if using a.m. or p.m. as in " The alarm will sound at 7 p.m.  I make my bed at 7 a.m. each morning".  Some believe that there are several optional conventions and can be ased on regional or typographical factors.
It is generally agreed that the correct way for writing Ante or Post Meridiem in professional writing is with "am" and "pm", with or without periods. This is recommended by the Chicago Manual of Style. However, there is no clear rule as to whether this should be written in capitals or lower case.
The preferred abbreviation depends on the style guide.
Several conventions exist to abbreviate  ante meridiem  and  post meridiem  - with or without periods and with capital or small letters.  The latest edition of the  Chicago Manual of Style  recommends  am  and  pm , with or without periods. Others maintain that the correct way to write a precise time is AM or PM.   The choice may be made based on regional or typographical factors. However, some say that here is no need to spell out times in an essay, although you might in creative writing or prose.
The best way to write times may depend on regional or typographical factors and there may even be no need to spell them out at all. Similarly, there is no clear agreement regarding how to write ante meridiem or post meridiem, with suggestions including lower case, upper case and with or without periods. You might consider writing "11:45 PM" as "Eleven forty-five in the evening".