Many people are just realising what AM and PM mean, and they've been getting it completely wrong for years.
The abbreviations, used to refer to the morning, and afternoon and evening, have quite the history behind them. Some people believe AM stands for "after midnight", while PM means "past" or "post" morning, or midday.
But these are not the true meanings behind AM and PM, the Mirror reports.
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Lots of social media users were taken aback to discover this after one inquisitive woman questioned what the two terms mean. On TikTok, @amayaclarke0 8 asked: "What does AM or PM actually stand for?"
In response, lots of viewers were quick to admit they did not know. Others tried to guess the answer, but this is turn revealed several weren't quite sure of the origins.
Replying to the English teen's video, which gained thousands of views, one commenter guessed: "At morning and past morning." A second joked: " Andy Murray and Post Malone." And several commenters confidently answered: "After midnight, and past midday."
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.
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