The only way to adjust leave is through the adjustment process in payroll. The problem is that you have to either input negatives or positives into one of two fields - accrual or taken, which then updates the balance at that point. Well, there are times where we DON'T want to adjust either because of POLICY. The adjustment is not an accrual adjustment or a taken adjustment.
For example, we have a policy of allowing donation of leave to other employees. The positive adjustment for the donee and the negative adjustment for the donor should not be reflected in the accrual or the taken fields. This is especially important if you have limits on accruals. Because it seems if you have a company limit of 160 hours for vacation balance, and a donee happens to have a balance of 100 hours in accrual transactions for the year (not "balance") and gets donated 120 hours from others in a time of need, it stops accruing when the person comes back from leave - because they've reached the limit for the year. They are working and should still be able to accrue leave until the end fo the year. So, adjustments have to continually be made.
By the way, this would also be prevalent in dealing with terminated employees who might forfeit leave that they're not entitled to, really. Maybe they're paid 80 hours of their balance of 160 because of POLICY. Sick leave is normally something that they get nothing on.
So, my idea is to add one more column (field) that can be used to adjust leave that is neither accrual nor taken amount. Since it's not TAKEN or ACCRUED. Totally an adjustment and should be reflected that way. My screen shot attached shows where this could be accounted for. And, this adjustment would adjust the BALANCE at the time, but would not affect anything that calculates accruals or taken amounts.