Plain-language rules behind the countdown boxes on /amendments.
Trusted validators are the servers each node has chosen to trust. For a change to turn on, more than 80 percent of them must vote yes. "More than" is strict: exactly 80 percent is not enough. That support must hold for 14 straight days. If it ever drops, the 14 days start over. Votes are counted only at a flag ledger, which is every 256th ledger, about every 16.5 minutes. The process starts at the first flag ledger after the 14 days are up, not the moment they end. In the next ledger after that flag ledger, about 4 seconds later, the network adds a system entry called EnableAmendment, which no person sends. In the ledger after that, about 4 seconds later again, the amendment is active, and its rules apply from that ledger onward. Once it is on, it stays on, and only a new amendment can remove it. A server that has not upgraded no longer understands the new rules and becomes amendment blocked, meaning it stops keeping up with the network until it upgrades.
It was deliberate. A validator operator publicly said he and Ripple switched their votes from yes to no, in coordination with other validators, just enough to reset the countdown — so Batch and its fix (in the new xrpld 3.4.1 release) could switch on together. Our page recorded the exact roll call where it happened.