Rusty has a variety of servers with different wipe schedules,
Most servers wipe every Thursday whenever Facepunch releases their update, usually around 3PM EST / 8PM GMT.
Some servers wipe every other Thursday (2 Week Wipe servers) around the same time, when Facepunch update is released.
Uber servers wipe every Tuesday and Friday (4PM EST for US / 4 PM GMT for EU).
All Blueprints wipe whenever a server wipes.
NoWipe servers wipe the first Thursday of every month whenever Facepunch update is released.
To find out more, check out the Servers tab in the website, or, to find out the next wipe simply type /wipe in game.