What is time?Time is a measurable period during which an action, process, or condition exists or continues. It is often referred to as the fourth dimension, along with the three spatial dimensions. Time as a unit is any particular time interval, used as a standard way of measuring or expressing duration.
InputHour is a unit of time conventionally known as 1/24 of a day. Since it varies between seasons, it is made constant by defining it to be equal to 3600 atomic seconds.
Month is approximately as long as a natural period related to the motion of the Moon which is about 1/12 of a year.