The guild traders are switched on Tuesdays at 3:00pm EDT for North America, and at 20:00 GMT for Europe (with all bidding closing 5 minutes prior.) After this point, traders begin displaying the stores of whichever guilds bid the highest for each of them. The new stores will then be accessible by the general public for an entire week. If your guild was outbid, your bid will be refunded back to the guild bank. After the trader switch, if not even a single bid was made for a certain guild trader, anyone will be able to walk up to that trader and immediately hire them for a set amount of 10,000 gold. This process is first come first served.