With a February use year you can bank 100% through July 31st (which is six months), 50% through October 31st (which is 9 months), and 25% through November 30th (which is 10 months). The only hitch is that these percentages are limits for the year. So if you bank 50% by July 31st, you do not get to bank the other 50% by October 31st since you have already banked the limit for beyong six months. If you want to bank 100%, you have to do it all during the initial six month window.