You can use the User Defined Calendar Type to compute the per day salary based on the variable days for each month based on Pay Heads such as Basic Pay. For example, 25 days in January, 24 days in February, 26 days in March, and so on.
Note: You must configure the value for the number of days in each month (period) before recording the attendance details using an Attendance Voucher.
To create the User Defined Calendar Type
Go to Gateway of Tally > Payroll Info. > Attendance/Production Types > Create.
Specify the required Name for Attendance Type.
Select Primary in the Under field.
Select User Defined Calendar Type in the Attendance Type field.
Press Enter to save.