Quota generation based on years of service

Dear Experts,

Please guide me on the below scenarios

leave year is April- March

Quota is 21 days per year.

if employee completes 5 years in April we need to add 1 extra day to the quota i.e. 21+1= 22 days, 6 years 22+1=23 in April month, likewise for rest of years..

1) On April 1, for everyone a check the on the years of service completed will be done and the appropriate amount credited on 1^st of April( here i need to check if an employee completed 5 years on 01st of April or not, if completed need to give 22 days from 1st of April, if not completed on 1st April then i need to check when he/she completing 5 years based on date type maintained in IT 41 and need to add that extra one day to 21 days quota which was already generated on 1st April)

2) When an employee completes 5/6/7/8/9/10 years of service in the middle of the year, an extra day will be credited (up to a maximum of 27 days per year)

Please guide me how to handle these kind of scenarios..

Thanks in Advance...

Thanks,

VS