We will learn the relationship between the 12-hour system and the 24-hour system.

Before that, you need to know that time is measured using multiple units.

Among them are:

[second], [minutes], [hour], [day], [week], [month], [year], [decade], [century], [millennium]

• a.m. means ante meridiem. The time represented a.m. is after midnight to before noon.

• p.m. means post meridiem. The time represented p.m. is afternoon to before midnight.