People are just realising what AM and PM mean

The terms are used to refer to the morning and the afternoon.

LONDON (Web Desk) - People have been left amazed after learning the history behind the abbreviations. While it should not come as a shock 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 .

However, the terms mean  before midday  and  after midday . As Royal Museums Greenwich, the home of Greenwich Mean Time, explains: "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, according to the experts. "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."

So, there you have it. If the Latin behind the abbreviations is news to you, you ve likely still been using them as the right time of the day, unless you ve been talking about noon or midnight specifically. If you have then don t worry, as it sounds like you probably weren t the only one.