Hello! Very nice article. I have a couple of questions if you don't mind.

When doing the last streaming of the wal from the primary the article mentions that the nodes will catch up to replication time `T`.

How do the nodes coordinate this time `T`? Is it simply just choosing a time in the future (after the backup has started) and waiting till they all catch up or is there more realtime coordination happening?

Also, in another part it's mentioned that "Time T is saved to ensure we know the precise time, down to the second, included in this backup." My question is that if 1 second is granular enough? I'm assuming that this is a simplification for the sake of explanation and Time T is a timestamp with at least millisecond granularity. I regularly play with otel data that can have nano-second granularity so I'm assuming is millisecond or more