It is essential to check your tyre pressure every two weeks when the tyres are cold (i.e. a tyre that has not run for at least two hours or has run for less than 3 km at a reduced speed). Ensure that you make adjustments if you take the pressure after riding, i.e. with "hot" tyres. In this instance, refer to the manufacturer's recommendations.
These recommendations are applicable for tyres used on the road. There are additional recommendations for use on the racetrack and more generally for any race.