Sorry but Shan is WRONG AM = 0:00 - 11:59 PM = 12:00 - 23:59 AM starts AT Midnight! PM starts AT midday!

PM=post meridian=afternoon=after 12 o'clock AM=ante meridian=forenoon=after 0 o'clock

very simple to remember .... we have 24 hrs in a day. So, let's split it up into two equal halves of 12 hrs each. Remember, 12'o clock (mid day) is Noon .... Neither AM nor PM. Similarly, 12'o clock at night is mid night..... Neither AM nor PM. Now 12'o clock (Noon) + any time (till 12'o clock Midnight) = PM And 12'o clock (Midnight) + any time (till 12'o clock Noon) = AM So, 3.50 (at night) should be 3.50 AM. AM starts immediately after 12'o clock Midnight. PM starts immediately after 12'o clock Noon (Midday). The abbreviations AM and PM refer to Meridian which is 12'o clock Noon. AM = Ante (before) Meridian ** "Ante" is a Latin word PM = Post Meridian Since 3.50 in the middle of night is before Meridian (12'o clock Noon), it should be 3.50 AM. All the best!!