Is noon 12 am or 12 pm?

‘Noon’ means ‘midday’ or 12 o’clock during the day. ‘Midnight’ refers to 12 o’clock during the night. Simple right?

Well, maybe not, especially if you’re using a 12-hour clock.

When most people say 12pm, typically they’re talking about the middle of the day: 12 noon. When they say 12am, they normally mean 12 midnight.

While most people follow this convention, technically it’s not quite right – as you’ll see from the definition of am and pm below. To avoid any confusion (and to make sure you arrive on time), it might be best to say 12 noon or 12 midnight instead.

Alternatively, you could use the 24-hour clock system, where 12:00 is noon and 00:00 (or 24:00) is midnight.

What does am and pm mean?

The 12-hour clock divides the 24-hour day into two periods.

• am stands for the Latin ante meridiem, translating to “before midday”. This is the time before the sun has crossed the meridian.
• pm stands for post meridiem or “after midday” – after the sun has crossed the meridian.

At exactly 12 noon, the Sun is at its highest point in the sky and directly over the meridian. It is therefore neither ‘ante’ (am) nor ‘post’ (pm) meridiem. At 12 midnight it also neither am nor pm.