Calculating Post-9/11 GI Bill® Usage
Post-9/11 GI Bill entitlement use calculations are made based on the rate of pursuit figured by taking the number of credits you are taking, times 30 days per month, divided by the number of credits considered full-time by the school.
So, if you are taking the minimal number of credits the school uses as their full-time floor, you would use up one month of entitlement for each month of school. But if you are taking, for example, 10 credits, and your school considers 12 to be their full-time floor, then you would use up 25 days of entitlement for each month of school (30 days x 10 credits = 300 credit days ÷ 12 credits = 25 days).
The VA adjusts how much entitlement you have left based on months and days and not a straight percentage. That is how you can end up with a certain number of months and days of entitlement left instead of just straight months.