During a discussion of this question, this conversation occurred on The Bridge: http://chat.stackexchange.com/transcript/message/3671820#3671820

The key point is this phrase:

Entries will be open until Friday 3/2 at 12pm EST. Selected entrants will be notified promptly.

Depending on your definition, "12pm EST" could mean:

  • Noon EST, because 12:00 pm is the first minute of the afternoon
  • Midnight EST, because 12:00 pm is the last minute before morning

Other questions, such as this one, provide the time in EST and UTC, which eliminates confusion.

Should providing time in UTC as well as in the local time zone be considered 'best practices'?

  • I'm in favor of using both. It's not much more effort, and save everyone else a lot of thinking. – John the Green Mar 3 '12 at 4:34
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    In standard usage, 12 PM refers to noon, 12 AM refers to Midnight. I'm sorry if this confuses you, but while there are several arguments you could make for using UTC, this should hardly be one of them. – LessPop_MoreFizz Mar 3 '12 at 5:17
  • @LessPop_MoreFizz - apparently, at least one person found it unclear: chat.stackexchange.com/transcript/message/3671861#3671861 – Steve V. Mar 3 '12 at 5:23
  • It seems there is a whole topic dedicated to this: en.wikipedia.org/wiki/… - however, convention is that 12 am is always midnight. – Resorath Mar 3 '12 at 9:03
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    Clearly we should be using CET – badp Mar 3 '12 at 10:01

No, they are fine. For these giveaways, you should not presume to impose an additional onus on the hand that feeds. Be happy they happen at all. The air of SE is pragmatic, not hyper-politically correct.

I'm sorry if you do not understand the given times (as mentioned, '12p = noon' is standard in the US, which is where this site is located), but feel free to ask in chat for clarification.

  • 6
    It's not just standard in the US, it's standard everywhere in the world that uses this convention for timekeeping to the best of my knowledge. – LessPop_MoreFizz Mar 4 '12 at 3:11
  • @LessPop_MoreFizz Apparently not in Japanese legal settings, according to Wikipedia. Although that really sounds like something someone just made up. – user3389 Mar 4 '12 at 4:34
  • @MarkTrapp It's based on this page, and while I'm admittedly not a Japanese speaker, it seems to be reaching to call the Japanese convention for timekeeping explicitly reversed. – LessPop_MoreFizz Mar 4 '12 at 8:11


  • Times should be posted in UTC as well as in whatever other local time zones are desired.
  • If this is impossible or impractical, care should be taken to avoid the use of the ambiguous 12am / 12pm, instead substituting "noon" or "midnight".
  • "11:59 am / 11:59 pm" or "1159 / 2359" are both better than "12 am / 12 pm".
  • 12AM/12PM should always be avoided. 12 Noon and 12 Midnight are better, but still less than ideal (especially for midnight). Times should be given as "12:00PM EST Friday (0500 UTC Saturday)" or "12:00 Noon EST (1700 UTC) Friday". Note the 24h clock and lack of :. – MBraedley Mar 3 '12 at 4:56
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    I support "European" or "Military" time, where you go from 0:00 (midnight) to 12:00 (noon) to 23:59 (one minute before midnight). – Raven Dreamer Mar 3 '12 at 5:30

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