Chances are, based on how poorly leap seconds and TLS 1.3 (and, I predict, http3/udp) are handled in actual reality by deployed systems, that a variety of software and hardware will fail inside infrastructure worldwide when ntp ticks over to era 2.

https://news.ycombinator.com/item?id=28046997

https://news.ycombinator.com/item?id=13750379

https://news.ycombinator.com/item?id=27402222