Answer: Year
Step-by-step explanation:
Revolution of the earth can be defined as the time which is taken by the Earth to move around the sun. The rotates on its own axis and revolves around the sun.
It takes 365 days and 6 hours by the earth to move around the Sun. It moves on a fixed path known as the orbit.
The 6 hours gets added every year and after 4 years it becomes 1 day and forms a leap year which has 366 days.