I try to run my automatic chronos at least once a month, but it never really occurred to me to run my quartz chronos regularly. Two of mine (6000 and Kirium) are now getting 'stuck' at random intervals and presumably need servicing - to be fair they are both 20+ years old and as I've only had them 2-3 years I have no way of knowing if they've ever been serviced. Makes me think though that it might be worth running my other 3 quartz chronos regularly to keep the oil moving. It's a bit annoying to have to send them in to be fixed as I don't actually ever use the chronographs for timing anything! Maybe in future I'll stick to three handers!