Pick any two:
1. 86400 seconds a day
2. SI seconds
3. Noon synced up with the sun
With UTC, we drop 1.
With UT1, we drop 2.
With TAI, we drop 3.
Maybe we should have gone with TAI, or with UT1 - I think that's what Julia does, sort of:
1. 86400 seconds a day
2. SI seconds
3. Noon synced up with the sun
With UTC, we drop 1.
With UT1, we drop 2.
With TAI, we drop 3.
Maybe we should have gone with TAI, or with UT1 - I think that's what Julia does, sort of: