The legacy Vault

Hello everyone. I was wondering when is the closest time from now in which the legacy vault will open ? i know it opens every year or around a special event like the harrowing etc, but I wanted to know if you guys have any ideas/info as to when is the closest time ? specifically in which month can i expect it to open ? I am asking because there are some skins that i just CANNOT wait to buy. These include: Underworld wukong Underworld twisted fate Feral warwick Zombie brand Noxus poppy Vandal gragas Alien invader heimerdinger

So like i said i would reaaally appreciate it if anyone can provide me with a specific date ( i know that it might be impossible to pinpoint an exact date but anything close to it, an approximation, would be nice ) also i would like to know if the skins i mentioned above will be there once the legacy vault opens. Thank you guys in advance :D.

oops, forgot to mention another awesome skin i want along with the others mentioned above, Ravenborn leblanc :D