Understanding PCR Rule based on Calendar Days

I wrote a small rule . The basic Pay should divide according to calendar days and should show an amount on Basic Payslip Amount.

But it is showing 2000

If I excute in the month of April If Basic Pay is 1000 It should divide by 31 days in a month and that should show as 32 . But it showing as 2000

same in case with other months if it is 30 days it should show as  33 How can i achieve that