The clear aligners need to be worn almost 24/7. The minimum recommended time is 22 hours a day. You only take them out when you eat, drink, or clean your teeth. Having said that, you can remove them for certain occasions. For example, if you do sports like swimming and are worried that you will lose the aligners in the water, or if you are out for a special event and are concerned that you may lose the aligners. The harm of losing the aligner is usually greater than not wearing the aligners for a few extra hours.