Your support page says:-
Below, you’ll find the new day and time when Guild Traders will switch over:
European (EU) megaserver: Tuesdays - 13:00 UTC, 10am EDT / 9am EST
13:55 Tuesday UTC: All bidding and renting from the previous week will stop
14:00 Tuesday UTC: Tabard of the selected vendor flips to new owners
14:05 Tuesday UTC: All bidding and renting is opened up again for the following week
This info contradicts itself, is the switch happening at 13:00UTC or 14:00 UTC ????
Further down your support page it says:-
What this means for the previous week: Traders will switch over normally on Sunday, August 3rd. Bids that take place after that will go towards a trader that will be awarded on the August 11th swap. That means Guilds will have traders for about 2 extra days following the August 3rd switchover. Once the August 11th switch over takes place, the traders will be back to the weekly cadence.
Again this info is wrong as last Sunday was the 2nd not the 3rd
FInally, although we are currently on an EU character copy on the PTS I am assuming that you will be testing the NA timings for the PTS trader switch as in game the countdown for the trader swap is showing as changing at 7pm UTC today (Tuesday 8th August) which would match the NA changes.