Privilege Leave +ve time

Hi Experts,

Greetings for the Day.

I have one issue (positive time) with Privilege Leave Quota

Every four months 10 days privilege leaves will add Privilege leave quota.

Ex: 31.12.2014- 10 days added

1. 30.04.2015- 10 days added
2. 31.08.2015- 10 days added
3. 31.12.2015- 10 days added.

But while executing PT60-31.03.2016 added 10 days Privilege leave.(wrongly added)

But actually it should add 30.04.2016.

Kindly provide me the solution to resolve the issue.

Regards,

Chandra.