How to prepare the payslip - 20 days salary (joining in the middle of month)

One candidate joining in the middle of month the salary for 20 days how to calculate. pls guide me

Dear Gomushan
Calculate on a pro-rate basis
For Example: 10000/30 *20

ok
but the basic , hra, etc , payslip

Use same formula suggested by Mr. Moses for each components divided by no. of days of the month.
Salary components February 2018 March 2018 April 2018
Basic Rs.6,000 6000x20/28=4286 6000x20/31=3871 6000x20/30=4000
HRA Rs.3,000 3000x20/28=2143 3000x20/31=1935 3000x20/30=2000
Conveyance Rs.1,500 1500x20/28=1071 1500x20/31= 968 1500x20/30=1000
__________________________________________________ _________
TOTAL Rs.10,500 10500x20/28=7500 10500x20/31=6774 10500x20/30=7000
Hope you will understand the above calculations.
Suresh