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by RijilV 1818 days ago
It’s a good read, and I really wish time was always that simple. Sometimes you have multiple platforms on different clock systems and distributed systems running across them. Did you know google and amazon smear leap seconds? GPS/Galileo/that-China-one don’t have leap seconds (but all are different TAI offsets) but that Russian GPS one does have leaps. They all have slightly different versions of utc.

Most of the time none of that matters and you can just install chronie and point it to whatever.pool.ntp.org and you’re off to the races. But boy does it suck when you have to to know.

2 comments

> GPS/Galileo/that-China-one don’t have leap seconds (but all are different TAI offsets) but that Russian GPS one does have leaps. They all have slightly different versions of utc.

This is not wrong, but it's missing a large chunk of information. All non-UTC-based geonavigation satellites also broadcasts both the offset between internal and UTC and if there's an impeding leap second.

You can nowadays buy a chip-scale atomic clock for $2000, which is a modest fraction of the price of an entire server. Every datacenter should have one.