Yes, British people use a.m. and p.m., though they are more common in writing or formal situations. In daily conversation, it is generally more common to say "in the morning," "afternoon," or "evening" (e.g., "6 in the morning") rather than "6 a.m.". While 24-hour time is frequently used for schedules, 12-hour is used colloquially.
Phrases such as y bore ('(of) the morning'), y prynhawn ('(of) the afternoon') and yr hwyr ('(of) the evening') are used to distinguish times in 12-hour notation, much like Latin a.m. and p.m., which are also in common use, for example 9.00yb (09:00) as opposed to 9.00yh (21:00).
Most people personally use 12 hour morning/afternoon/evening time (rarely directly saying am/pm). Most publish schedules (TV, transport, etc.) will use 24hours.
The Latin abbreviations a.m. and p.m. (often written "am" and "pm", "AM" and "PM", or "A.M." and "P.M.") are used in English (and Spanish). 'Noon' is not abbreviated. When abbreviations and phrases are omitted, one may rely on sentence context and societal norms to reduce ambiguity.
Two other common abbreviations are a.m. (`before noon') and p.m. (`after noon'): 10.00 a.m., six p.m. These are always acceptable. Note that these are not capitalized in British usage (though American usage prefers (A) 10.00 am and six pm, with small capitals and no full stops).
You can either say: "quinze heures quinze" (military style 24 hour clock) or "trois heures et quart" (colloquial 12 hour clock). With the 12 hour style, you can also add "du matin" (a.m.) or "du soir" (p.m.) to remove any lingering ambiguity.
There is no genuine confusion nor ambiguity only a self-made one. As the day begins at midnight, midnight must be 12am. The moment of noon is in the first second, consequently minute and hour of the afternoon therefore noon must be 12pm.
Some of the earliest timepieces were sundials. In the northern hemisphere, the shadow of the dial traces clockwise as the sun moves through the sky, so when clocks were being developed in medieval times, their hands were made to turn in the same direction.
We associate PM with the afternoon and evening. The term pm is an abbreviation of the Latin 'Post Meridiem', which translates to 'after midday'. These indications of time are centred around Midday as this is how the 12-hour clock functions.
It's too informal and too intimate when you're talking to a teacher. Maybe in your culture, calling a woman “Mum,” “Ma” or “Sister” would be a sign of respect. In the UK, it's actually informal and affectionate rather than respectful. You shouldn't say it to somebody that you don't know.
Where Is the 12-Hour Format Used? Most countries around the world today use the 24-hour system. However, the 12-hour format, including am and pm, is officially used in a number of countries, including the United States, Canada (except Québec), Australia, New Zealand, and the Philippines.
Referring to time, “six oh five” (am or pm, unless you are using a 24 hour clock). Or “five (minutes) past six”. The convention for writing time is to use a colon, not a. period. 6:05 or 06:05 / 18:05.
At minute 45, we say it's “quarter to” the next hour. For example, at 5:45, we say it's “quarter to six” (or 15 minutes before 6:00). At minute 30, we say it's “half past”. So at 9:30, we would say it's “half past nine” (or half an hour after 9:00).
NIST researchers have made the most accurate atomic clock to date — one that can measure time down to the 19th decimal place. This “quantum logic clock,” under continuous development for 20 years, relies on quantum computing techniques that pair an electrically charged aluminum atom (ion) with a magnesium ion.
The minutes are written with two digits; the hour numbers can be written with or without zero padding (02:05 or 2:05). In oral communication, 12-hours are prominently used since 24-hours are considered very formal. In 12-hours, hour figures are always preceded by the definite article and a.m. or p.m. are never used.
