How the balance will be calculated in terms of carryover.

Summary:

We have a new carryover limits based on location wise from October 1st onwards. here now one employee is having 60days of leaves and as per the new requirement 40days will be carryover to the next period but here the issue is before October 1st the employee is having 60days so he already used his balance to book in October and November and December in this case how the system will calculate his balance here the repeating period is monthly.

Content (required):

We have a new carryover limits based on location wise from October 1st onwards. here now one employee is having 60days of leaves and as per the new requirement 40days will be carryover to the next period but here the issue is before October 1st the employee is having 60days so he already used his balance to book in October and November and December in this case how the system will calculate his balance here the repeating period is monthly.