Comment by wowczarek

I also see this as a defeat. BIPM's Bulletin C announcing the leap second or lack thereof, is almost always very close to full six months before the event. Even this is almost enough time to both develop and test an implementation, not just test it, plus there are usually years of no action between the events.

> Instead of changing the time definition it would make much more sense to switch to TAI for me.

Should UTC permanently stop diverging from TAI, it is more likely that the opposite would happen - TAI would be subsumed by UTC, because there would be no need to maintain two timescales.

Systems which prefer not to deal with discontinuities already use TAI. Many packet capture / timestamping systems natively operate in TAI, and UTC conversion is/can be done in "post-processing". Many / most time servers also do internally, and for example the native time scale for IEEE 1588 / Precision Time Protocol is TAI, and UTC->TAI offset and leap events are announced separately. NTP though, while using its own epoch, is still UTC aligned and while it indicates the LS events, it operates on discontinuous timestamps.

TL;DR: Time sync hard; must make easy.