> I’ve been researching how online time services sync over HTTPS HTTPS isn't usually used as far as I'm aware. Wait until you discover that your time server's

> I’ve been researching how online time services sync over HTTPS HTTPS isn't usually used as far as I'm aware. Wait until you discover that your time server's TLS certificate has "expired" according to your local machine; or hasn't yet become valid (valid in the "future"). Good luck syncing after that! Most services use some version of NTP; here's NTPv3 spec: https://datatracker.ietf.org/doc/html/rfc1305 https://datatracker.ietf.org/doc/html/rfc1305 but there are others. > Due to network latency & asymmetry, even widely trusted time sources can drift by ±50ms or more Yup! Some people would call that a feature to enable leap second smearing. > most public clocks are way less accurate than we assume I would bet you're right but I don't recall any studies to measure how bad the problem is. It sounds like you might be barking up somewhere with possibility for unique studies and information! > Some engineers are experimenting with ways to push accuracy below 10ms Get rid of HTTP and you can get accuracy below 1ms. HTTP takes up a lot of compute compared to NTP.