PF Constant is maintained not picking

Hello Frnds

* PF Constant is maintained for 15,000

* PF is getting correctly calculated for old employees

When an employee is joining in the mid of the month and Basic Salary is still above 15,000 the PF Contribution is getting pro rated for the monthly purpose .

Example : For new employee - Basic Salary is 33,250  ,Joining date 3rd Aug

what should happen         15,000*12/100=1800

currently happening = 1800/31 =58* 29 = 1683

Please guide how to correct this.

Regards,

RA