I was recently given a deadline of 12pm, which is meaningless by definition. The abbreviations ‘am’ and ‘pm’ mean ante meridiem and post meridiem – before and after noon. 12 noon cannot be either before or after noon because it is noon. 12 midnight is both before and after noon, and by the same margin.


The culprit had at least three alternative ways to express him/herself:

  • Words: ‘noon’ or ‘midnight’.
  • 24-hour clock: ‘1200’ or ‘2400’.
  • One-minute-off: ’11:59am’ or ’11:59pm’.

Airlines usually combine the last two of these for midnight departures or arrivals, to avoid any confusion about the date.

Don’t mind me: I’m just letting off steam. I’m sure none of my readers would be guilty of such an elementary mistake.