The terms "a.m." and "p.m." are abbreviations of the Latin "ante meridiem" (before midday) and "post meridiem" (after midday). Depending on the style guide referenced, the abbreviations "a.m." and "p.m." are variously written in small capitals ("" and ""), uppercase letters without a period ("AM" and "PM"), uppercase letters with periods, or lowercase letters ("am" and "pm" or, more commonly, "a.m." and "p.m."). With the advent of computer generated and printed schedules, especially airlines, the "M" character is often omitted as providing no additional information as in "9:30A" or "10:00P".