Mike,
The usual life of a bottle is five years, if it is stamped with a star, then it's 10 years from the printed date. That date only applies to transportation, and not useage. ie...if it is past its inspection date, it can still be use 'legally' but cannot be transported by public roads.
That is covered by 49 CFR, which only applies to Intrastate and interstate commerce, so if it's for personal use, the expiration dates on the bottles are irrelevent.
Tim