Do it once or twice a day. Because it is not weight training, more of a functional balancing activity breaks arent necessary as youre not achieving 'progress' by ripping muscles apart. You should be fine.

This is very good for you too so well done :)

bruce lee also do it everyday,when he is taking off his shoes, he likes to do it with one leg balanced.

I do it blind folded for the full length of a song (usually 3 to 4 minutes- then restart the song with the other leg). Does this require a rest day, or is balancing on one leg something that should be done every day? Also, how many times a day? If I should do it multiple times for each leg, how long should I rest between each set?