People are only just finding out what AM and PM actually stand for

You might have spent years using the abbreviations AM and PM in daily life in full confidence that you knew what they meant but you could be wrong. People have been left gobsmacked after learning what it actually stood for, and it wasn’t at all what they thought.

AM and PM - what does it actually mean?

People have been left amazed after learning the history behind the terms AM and PM. While it should not come as a shock that the terms are used to refer to the morning and the afternoon, you might be surprised to realise AM does not stand for 'after midnight', while PM isn't quite the same as 'past morning'.

Social media users were stunned to discover this fact after one inquisitive woman questioned what the two terms mean.

In a post to TikTok, @amayaclarke08 asked:

What does AM or PM actually stand for?

What the abbreviations actually mean is the following.

According to the Royal Museums Greenwich, the home of Greenwich Mean Time, 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.

It is, for this reason, you shouldn't call midday 12pm, the experts advise. 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 is also neither AM nor PM.

Confused reaction

If the Latin behind the abbreviations is news to you, you've likely still been using them at the right time of the day, unless you've been talking about noon or midnight specifically.

Lots of viewers on social media were quick to admit they did not know the meaning behind the capital letters.

Others tried to guess the answer, but this in turn revealed several weren't quite sure of the origins.

One TikTok user suggested:

At morning and past morning.

A second one joked:

Andy Murray and Post Malone.

And several commenters confidently answered:

After midnight past midday.

But it’s good to have some clarity from the experts now.

Sources used:

- Mirror: 'People are only just realising what AM and PM mean - and many guessed wrong answer'

- Royal Museums Greenwich