What does 12pm mean

However, an English authority says that it refers to midnight. Original Post. David, Moderator Moderator. Hello, Ms. Tan, You are correct. I second that. Your "English authority" needs to do a little brushing up.

Interestingly, one can "prove" that 12 p. RM Rachel, Moderator Member. From: AM and PM wwp. This means that It is after Noon that P. What is Noon and Midnight? This means that A. If all these questions about time have got you in a spin, why not visit the Royal Observatory , where many more mysteries of time await Which years are leap years and can you have leap seconds?

Because the Earth takes a little over days to orbit the Sun, we need to make adjustments to keep the seasons from drifting: leap years and even leap seconds. How do we divide time? While days and years are fairly neat astronomical events, what explains months, weeks, hours and minutes?

Why do we have daylight saving? When do the clocks go forward in ? Marking the start of British Summer Time, the clocks 'spring forward' in March, meaning we'll lose an hour's sleep When do the clocks go back in ? Marking the end of British Summer Time, the clocks go back in October, giving us an extra hour in bed Discover gifts from the home of time Learn the story of Greenwich Mean Time.

Midnight is when it changes back. Noon is 12pm, midnight is 12am. Midnight is the transition time from one day to the next — the moment when the date changes, on the local official clock time for any particular jurisdiction. By clock time, midnight is the opposite of noon, differing from it by 12 hours. Because of the potential for confusion, it is advisable to use 12 noon and 12 midnight. Whoever was in charge of deciding these things decided on the current system and everyone has stuck with it since.

AM means ante meridiem and Pm means post meridiem, or before and after midday. The reason for the separation is that all the minutes of the hour PM are after midday. Since 12 noon is Meridiem, it cannot be placed in both am and pm. Active Oldest Votes. Improve this answer. Wikipaedia is all very well but I would not wish to rely on that if catching a flight from London to Melbourne which left at You have also not answered the point about to which day 'midnight' belongs.

WS2 You are straying into legalese here, which is considered off-topic. But we warned the pupils that they might encounter 12 pm, when it should by convention mean 12 noon, but might be being used wrongly. I agree that legalese should cite or to disambiguate 'midnight', but these are decisions that need to be taken by proper czars rather than grammar czars.

Add a comment. Tim Jansen Tim Jansen 1 1 bronze badge. Who says? And would that be This is what NIST has to say about it: nist. There is ambiguity all over the place here Tim. And have you noticed, that the more ambiguous things are, the more certain, and vituperative in their certainty, people become.

But the link that Mari-Lou provides to an earlier post does clarify most of this very effectively indeed.