The amount of time that you spend wearing the Invisalign retainers will directly correlate with how quickly you achieve desired results. To meet the standard timeline of 9 to 12 months for the entire Invisalign procedure, it is recommended that you wear the retainers for at least 20 to 22 hours per day, and only really take them out to eat or drink (anything other than water). They only work while they are being worn, so while it is ok if they are out for a couple of hours for a special occasion or night out, it is recommended that those occasions are avoided as much as possible to ensure that your treatment is kept on track. Additionally, the longer you go without wearing the retainers, the more uncomfortable it may be when you put the retainers back in, as your teeth may have started to regress back into their previous position without the gentle pressure being applied by the retainers. Simply put, wear your retainers as much as you can while still ensuring that you are taking them out while eating and drinking and for proper cleaning and hygiene to make sure that you are able to achieve the desired results as quickly and painlessly as possible.