People are just discovering what AM and PM means

I was today year's old when I found out what AM and PM mean.

Prepare to be relieved someone else didn't know either:

It feels like a pretty irrelevant detail to have to remember in most people's day-to-day life when your head's filled with when you need to do you taxes by, if anyone's fed the dog or what's for dinner.

People are flooding to social media in bewilderment after only just clocking what AM and PM actually stand for.

One user suggested the letters mean: "After midnight past midday."

Another commented: "At morning and past morning."

"After midnight and pre afternoon idk that's what I've been told all my life," a third added.

Alas, all of the suggestions aren't strictly correct.

The real meaning of AM and PM is 'ante meridiem' and 'post meridiem'.

Both names are derived from latin and AM means 'before midday' - before the sun has crossed the meridian - and PM, 'after midday' - after the sun has crossed the meridian.

"The 12-hour system divides the 24 hours of a day into two periods lasting 12 hours each. The first 12-hour period is designated as am. It runs from midnight to noon.

People have since flocked to social media in shock over only just realising what AM and PM stand for.

One user wrote: "32 times around the sun and I never knew."

"Thank you so much, I've been searching the meanings of those two for years, finally got it," another said.

However, one clever cookie boasted: "No, no need to wonder, knew that from primary school..pre decimal times."

And a final - who clearly paid a lot of attention at school rather than having a chit-chat, doodling or humming while looking out the window - resolved: "Are we really in a world where this is news?"