12-hour clock
The 12-hour time is common in several English-speaking countries and former British colonies (such as the United Kingdom, the United States, the English speaking parts of Canada or India), as well as a few other countries. There is no widely accepted convention for how midday and midnight should be represented: in English-speaking countries, "12p.m." means 12 o'clock noon, while "12a.m." means 12 o'clock midnight.