Yikes, that's cutting it too close for comfort!
We had to do the penciling in part early, so we could file FAFSA, but since we owed (which is fine, since it means we didn't overpay) we waited to mail them until the other day. Would've had both state and fed. in the mail on the 14th, but dh forgot to put the mailing label on the federal return envelope (which, fortunately, the postal worker caught!) so that got mailed on the 15th. Now I can relax until next year!