My employer approved my use of all vacation days in February and March, even though I technically should only accrue three per quarter. Now it is September and I am leaving the company. My employer notified me that I will have to pay them back for three days of vacation time, because I used it before I had earned it. However, it was their error to approve the use of it in the first place. It seems the employer should take on the liability for having made that decision, having taken that risk. I don't want to pay back those vacation days. Let me know if it's legal for them to demand that I do. Thanks.