I've got a flight back to my own country with American Airlines. And I'm just wondering what the departure time exactly means. It says 12:45 PM but when you say 12:45 PM, it should mean the middle of the night. Is it really supposed to be a quarter before 1:00 AM?? I'm pretty confused with this AM/PM stuff we don't really use in our mother tongue, thanks.

169 American Airlines Wi-Fi on-board    
12:45 PM
3:55 PM
Arrives August 3
11h 10m 789 Economy 
  • 3
    You've misunderstood the time. 12:45PM is just before one o'clock in the afternoon.
    – user90371
    Commented Jul 9, 2019 at 3:54
  • 1
    en.wikipedia.org/wiki/12-hour_clock Commented Jul 9, 2019 at 4:03
  • 1
    AM is between midnight and noon. PM is.between noon and midnight. It's quite simple really.
    – phoog
    Commented Jul 9, 2019 at 4:23

2 Answers 2


12:45 pm is also 12:45 o'clock in international time, i.e. 45 minutes after noon or 15 minutes before 13:00 o'clock.

Your flight leaves at 12:45 LA time. It takes 11 hours and 10 minutes so it arrives in Narita at 23:55 LA time. Japan is 16 hours ahead of LA, so the local time will be 15:55 or 3:55pm in American convention.

  • 2
    "o'clock" is only used for full hours, without the :00, and using a 12-hour clock. So 12:45, not "12:45 o'clock", and "13:00" (or 1 pm or 1 o'clock in the afternoon, or...), not "13:00 o'clock".
    – jcaron
    Commented Jul 9, 2019 at 11:56
  • Terms such as 13:00 o'clock or 12:45 o'clock are not used. The term o'clock is used after a number from one to twelve to say the time when it is exactly that hour: dictionary.cambridge.org/dictionary/english/o-clock Commented Jul 9, 2019 at 17:21
  • what I like about this answer is that it shows a way for others who are unsure about AM and PM to test their hypothesis by using the flight length and landing time. Commented Dec 12, 2020 at 19:32

PM is an acronym for the Latin post meridiem, which means 'after noon'. Your flight is scheduled to depart at 45 minutes after midday, i.e. at 12:45 hours.

AM stands for ante meridiem, which means 'before noon'.

  • This answer is only helpful if you know that the AM and PM start to work the minute after midnight and noon, not just after the next hour. (And if you are not familiar with AM and PM notations it is not that strange a thought.)
    – Willeke
    Commented Jul 9, 2019 at 19:27
  • 1
    @Willeke The statement "AM and PM start to work the minute after midnight and noon" implies, for example, that PM 'begins' at 12:01 hours. However, this is incorrect as 12:00:01 hours is also 'PM' or after noon. There is a useful discussion on the topic here: english.stackexchange.com/questions/28498/… Commented Jul 11, 2019 at 7:53

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