Every day. Takes some time to get through a rotation as I've been bitten badly by the bug. I always try to give the "biscuit tin" lesser models some wrist time too... it's not just about Omegas, Rolex, JLC's and Pateks....
I have been known to change my watch over the course of a day !
I wear 3 vintage (50s Omega, 60s Longines, 70s Longines) and 1 modern (90s Tiffany) on rotation. Generally it's the 70s Longines or the Tiffany while in the office and the vintage watches in the evenings and on weekends.
If my ship comes in, I may wear a new JLC some day, but I only love vintage Omega's to wear.
I love the history, I love the story, I love the "bump" when I move my wrist.
Actually, I do have a cheap Casio I wear swimming or gardening. It was given to me by a neighbor. I wouldn't risk a real watch.
I only own one modern watch and around 50 vintage. Never worn the modern omega, vintage to me is wear it’s at. If I had 10 000 I’d buy one of my vintage grails over anything modern, that’s just me though. So, everyday.
Like a lot of people around here, I have 2 modern, 8 vintage and wear daily a vintage piece. Never had a problem related to their age, but I must confess that I'm always more careful when I'm wearing vintage.
All of my watches range from 1962 (105.002) to 1987 (Holy Grail) and are being worn daily. Never had any issue besides some light scratches which contribute to their stories, isn't it?