Meaning of PM and AM
What are PM and AM:
AM and PM, are two acronyms of Latin origin, "A.m", in Spanish means "before noon", and "Post Meridiem" which translated into Spanish is "after noon." Both acronyms are used to refer to each of the 12-hour periods into which the day is divided.
Taking into account, the 12 o'clock system, the AM indicator is a period starting at midnight (00:00) until 11:59. Meanwhile, the PM indicator starts at noon (12:00) until 11:59 at night. The 12 hour system is used in many countries, such as: Mexico, Venezuela, Colombia, Uruguay, Honduras, Canada, among others.
For its part, the 24-hour system, also known as military hours, avoids the use of the acronyms AM and PM due to the continuous counting after 12 o'clock, for example: 1:00 p.m. is equivalent to 1 o'clock in the afternoon, and so on. successively. Currently, it is a widely used system, and preferred in writing to avoid confusion regarding the time when the events occurred.
However, there are countries in which they use both systems, using the 12-hour system in the informal dialect, such as: it is 5 in the afternoon, it is 3 in the morning.
The AM and PM indicators are observed in digital clocks to differentiate and allow the individual to have knowledge of the time, whether it is before or after noon, although there are digital clocks with the 24-hour system. In this sense, the individual must choose which system is best adapted to.
In English, AM (before noon) is "Before midday" or "Before noon", and PM (after noon) is "After midday".