What is full form of ampm?

The full form of AMPM is Ante meridiem and Post meridiem. It is a Latin term used to indicate the time of day before or after noon.

* Ante meridiem (AM) means "before noon". It is used to indicate the hours of the day between midnight and noon.

* Post meridiem (PM) means "after noon". It is used to indicate the hours of the day between noon and midnight.

The terms AM and PM are commonly used in the United States and Canada. In some other countries, a 24-hour clock is used instead.