The calculation of gratuity after 7 years in an unlimited contract

Hi,

For an employee who has finished 7 years, the gratuity would be calculated on 30 days' basic pay, or would it be 21 days for the first 5 years and subsequently to be taken as 30 days after 5 years or more?

The above query is based on the fact that the employee is on an unlimited contract.

It would be very kind if you could clarify in compliance with the UAE labor law.

Many Thanks!