How To Calculate Per Calendar Year Calculation Pro-rated Earned Leaves?

Hi,
One of the employee has joined on the 13th of June 2011. As per company norms, the employees are entitled to get 15 VL and 15 SL from Jan to December.
The first six months of the employee is considered to be the probation period wherein the employee is entitled for NO leaves.
So how to calculate leaves as per calendar year prorated earned leaves from his hired date with the Company?
Pls help me all of you here at citehr.
Thanks a lot in advance.

Dear Dayut,
Earned Leave are to be calculated as one day for 20 working days.
At the end of the calender year, you can calculate the no of worked days in that year, in your case june 13th to 31st dec 2011 divide it by 20 to arrive exact earned leave.Please note that earned leave are to be calculated from DOJ.
As per as VL and SL are concerned it can be arrived 15 divided by 12 ie 1.25 days per month, Suppose his DOC was 12 th Dec 2011 just 19 days left in that year then you can give one day each in VL and SL for 2011.
S.Sethupathy
Excellent HR Services.