The contact lenses have deadline. As far as i know, there are contact lenses for one month, a season, half a year etc. The longest time i wear is about three months ( a season). You shall listen to the sellers advices of how long you can be worn of the contact lenses for the sake of your eyes. Please don't wear contact lenses that are deadline. It may cause some eye damages.
As long as you take reusable contact lenses out at night and wear them during the day and you clean them regularly, the reusable contact lenses can last as long as its expired date. However, you should talk to your eye doctor about how long the reusable contact lenses can last when you go to get the reusable contact lenses. The doctorr there will give you some suggestions on how to take good care of the contact lenses. Just follow your doctor's instructions.