If you are active duty in any of the five branches of the armed forces or the National Oceanic and Atmospheric Administration (NOAA) you earn 30 days of leave (paid vacation) every year.
Military and NOAA members earn 2.5 days of leave for each month of service. Up to 60 days of leave can be banked (accrued) over a two year period, but your leave balance is checked on the first day of the fiscal year (October 1) and any excess leave above 60 days is forfeit.
If you have leave to your credit at the time of your discharge or re-enlistment, you may be entitled to sell it back. Leave is valued on the basis of the basic pay. Each day of leave is worth a single days basic pay.
Note: You can't receive payment for more than 60 days. Additionally you can't sell leave if you are discharged for the purpose of accepting a commission or a warrant in any uniformed service.