# Is there a name for the designation AM/PM?

**URL:** <https://boards.straightdope.com/t/is-there-a-name-for-the-designation-am-pm/417420>\
**Category:** Factual Questions\
**Created:** [August 29, 2007, 10:03pm UTC](https://boards.straightdope.com/t/is-there-a-name-for-the-designation-am-pm/417420 "2007-08-29T22:03:18Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![wankorama](https://avatars.discourse-cdn.com/v4/letter/w/35a633/32.png) [@wankorama](https://boards.straightdope.com/u/wankorama)\
**Post date:** [August 29, 2007, 10:03pm UTC](https://boards.straightdope.com/t/is-there-a-name-for-the-designation-am-pm/417420/1 "2007-08-29T22:03:18Z")

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…for example, if I write 4:00am and I mean to write 4:00pm, I would say “Oops, I used the wrong \_\_\_\_\_\_ after 4:00.”

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**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\
**Post date:** [August 29, 2007, 10:05pm UTC](https://boards.straightdope.com/t/is-there-a-name-for-the-designation-am-pm/417420/2 "2007-08-29T22:05:06Z")

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meridiem

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**Author:** ![Baffle](https://avatars.discourse-cdn.com/v4/letter/b/dec6dc/32.png) [@Baffle](https://boards.straightdope.com/u/Baffle)\
**Post date:** [August 29, 2007, 10:23pm UTC](https://boards.straightdope.com/t/is-there-a-name-for-the-designation-am-pm/417420/3 "2007-08-29T22:23:36Z")

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I call it a _temporal antecedent_. But only in everyday speech.

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**Author:** ![Ignatz](https://avatars.discourse-cdn.com/v4/letter/i/3be4f8/32.png) [@Ignatz](https://boards.straightdope.com/u/Ignatz)\
**Post date:** [August 29, 2007, 10:29pm UTC](https://boards.straightdope.com/t/is-there-a-name-for-the-designation-am-pm/417420/4 "2007-08-29T22:29:40Z")

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Or meridiem antecedent.

BTW, in a slight hijack, I contend that 12 p.m. actually is the same as 12 a.m., and they both mean midnight because the Latin a.m. means \*ante meridiem \* (before noon) and p.m. means \*post meridiem \* (after noon) Given this classic translation, noon would be 12 m. even though “midnight” starts with “m”.

This was shifted from GQ to GD a couple of years ago in this forum. Just 2 more cents’ worth…