Altis will be opened at 3PM GMT/BST. (Normal restart time)
The [SG] Mod has also updated, this is a required update for all servers, you must update it to be able to join our servers!
The update is around 150MB.
To force update it, you need to launch Arma 3 via Steam, right click on the mod and press repair. You can also try to restart Steam for an automatic download.