[bayindirh]

I recommend you read time keeping on the computer systems. Without NTP and some atomic clocks on the network, computers can't keep accurate time themselves.

And using a moving window / sun synchronization like that is just brave to put it mildly.

[0] https://blog.codinghorror.com/keeping-time-on-the-pc/

Also, there was an excellent article about clock drift, but I failed to find it.