There is no fixed answer to this. We aim to use it 3 times a day for at least 3 minutes each session. Getting into a habit is good so regularity of time and place definitely help. How about after you brush your teeth and before you go to bed? During times of stress or pressure at work why not take time out every hour to help you stay calm? Basically you can use it as often as you need to do. Little is better than never!