End of service calculation

what i have is an employee database and i want to apply the following
rules :
Employee Name
Total Package
Total Per Day
Additional days
Total Working Months
Total Working years
Type :Termination/resignation

If the employee is resigning before the completion of 1 year of
service :
He will be getting as benefits total working days -45 days of deduction
+ additional days


If the employee is being terminated before the completion of 6 month
He will get total working days+ additional days


If the employee is being terminated after the completion of 6 month
he will get 1 month salary + additional days