I topped up my tyres last 4days before the Tour of Flanders 26th of March to 105pri rear/ 95psi front. I tend to pump up once a week depending on the weather (sometimes less often if its icy). I was going to top this time on Friday or Saturday when I realised it wasn't going to be icy at the weekend but some oxymoron drove into the back of me on Wednesday so I decided my butt would appreciate the slightly smoother ride.