I check my psi 2-3x monthly, especially with drastic weather changes rolling in to stay awhile. Anytime I go to the dealership, tire shop, etc. I always check psi and lug nut torque within a few days as I simply don't trust them over what I already do. Surely they're adjusting based on what they see once the tires are somewhat hot from the drive there and I doubt they factor in current ambient temp for any type of offset.