I’m an time accuracy junky, and I have zero tolerance, which is why I have GPS/BT/RF controlled time syncing daily on my quartz movements. For mechanicals, I regulate them myself to be ~3s/day and at that, it makes me nvtz but it’s the best I can do for the 300 year old technology. I’m looking to buy some high end HAQ, and still waiting for my QT-8000B tester to get here, so I can super tune them to be +/- 5s/yr, and I’ll have to live with that. BTW, I got a Seagull ST1655 and ST1901 that both keep +/- 3s/day that I timegrapher tuned, I’m impressed, the keyless works is a tad janky but I can fix that