I'm sure that humans keep correctimg the time and planetary movements. The clock has to be wound upnon probably a daily basis and it's impossible for a non-atomic clock to be accurate for thst long. Even a quartz watch (without radio or internet time corrections) will be out by a few minutes each year. And that's without taking into account leap seconds. Which the designer could never have considered as they only started in 1960-1972 and are irregularly placed with only about 6 months notice.