The year consists of 12 months. Every month has a separate set of weeks and days. In a year, the 7 month has 31 days, the 4 month has 30 days, and 1 month has 28 or 29 days. February has 29 days in a leap year and 28 days in a non-leap year.
The time span of a Day is controlled when it takes the Earth to totally turn on its pivot, and are estimated through the time it takes the Sun to arrive at its most noteworthy point in the sky, two times successively. The Earth requires a year to finish one pivot the Sun.