If you the first time wearing contact lenses, you shall try to adapt it. In detail, you can wear two hours the first day, and four hours the next day, and six hours the third day..... And no matter how long you wearing, you shall take the contact lenses off and clean it everyday before you sleep for the sake of your healthy of eyes and the contact lenses. Good luck.
It may be as shorter as possible. If you wear the contact lenses for the first time, 2 hours may be suitable, 4 hours for the next day, and then increase successively. But less than 8 hours every day is better. You should not wear them during the night or wear them to sleep for a long time. However, some contact lenses have special design, you can wear it for 24hours, but not very often. But in any case, wearing contact lenses will result in different levels of chronic injury to your eyes. So you should be careful, and follow your doctorâ€™s instruction.