How to set up PDBA that gives 30 hours on first payroll of year, then at year end the unused balanc

We have a PDBA code set up that gives employees 30 hours of leave for bereavement at the beginning of each year.  We want the unused hours to be removed at year end, then on the first payroll give them 30 hours.  We just ran pre-payroll for the first payroll of the year and checked the leave balances.  For the PDBA I found that instead of having a beginning balance of 30 my balance is 60.  Employees that used hours, for example 16, now show a balance of 46.  It is like the balance was rolled over but we didn't