I went over a year without checking mine. The ride was so good I didn't even think of it untill I was loading up for a trip.

 

On going thing if I am riding bike a lot check about once a week if periods of bike sitting I check it every time I ride same with my tires.

 

Mine's never lost air in the 4 years I've had it after originally setting up the air pressure. Check it as much as you think you need to, it's easy to do.