The 12-hour system is a unique temporal principle that divides the twenty-four hours into a day in phases 2, am and pm. Am is derived from the Latin term ante-meridiem which refers to “before noon”, while from pm it derives post meridian which means “past midday”. Both the two periods have twelve hours numbered from 0 to 11, with 0 behaving like 12. Using 1 numerical 12 followed by pm or am, the 12-hour clock is able to identify all 24 hours in one day . The 12-hour system developed over time from the mid-2nd millennium BCE to the 16th century CE. The 3rd and the abbreviation used less in ” m ” derive from ” Meridies” which means noon or noon. The abbreviation ” m ” is rarely used, and if used in a statement can confuse people.
The history of the 12-hour system
Initially, there were periods 2, so one was drawn by the positions of the sun while the other period by the position of the moon. Over time this has evolved into the 12-hour system, which started at midnight and ended at noon. The use of the 12-hour system can be traced back to ancient Egypt and Mesopotamia. Egyptian watches dating back to 1500 BC were discovered in the tomb of Pharaoh Amenhotep. Both a sundial for daytime use and a water clock that was used to tell the time of night were found in the tomb. The Romans used a 12 o’clock watch for the day while sharing their nights in four watches.
The 1st mechanical watch was built in the 14th century, and in Europe the timers used the 12-hour system with the number written in Roman numerals. These watches used the double XII system which showed both am and pm periods. The XII double system can be seen in numerous surviving quadrants in Europe such as that of Exeter and Wells. During the 15th and 16th centuries, the 12-hour system gradually became standard throughout Northern Europe for public use and the 24-hour system was reserved for numerous specialized applications such as chronometers and astronomical clocks.
Which countries use the AM and PM system?
In many countries, the 12-hour system is the dominant spoken and written time system, especially in countries that were part of the British empire such as India, the United States, the United Kingdom, Bangladesh, India and Pakistan . Many other nations have followed this system, including Malaysia, the Philippines, Egypt and Mexico. Some countries use both the 24-hours system and the 12-hours system.
Noon and Midnight: PM or AM?
The most significant challenge with the 12-hour system is the confusion about the abbreviation to be used when referring to midnight or noon as neither time can be identified as pm (afternoon) or am (before noon). Most digital watches designate noon as 12.00pm midnight as 12.00 am, but the exact time at noon is neither am nor pm from the next hour to 12.00 is afternoon. Therefore, to avoid confusion, it is useful to use the names 12-midnight and 12-noon when writing. Another challenge with this system is the lack of a date designator. Therefore it is impossible to logically identify the right instant when a date is given as 12 am of December 9, 2017.