For EU:- The World of Tanks servers will be unavailable on 25.10.2018 from 06:00 – 06:45 CEST due to this update.

Please also keep in mind, that due to the actualisation:
Clan Portal (eu.wargaming.net/clans) will be unavailable from 06:00 CEST 25.10.2018 till 06:45 CEST 25.10.2018

There is no information for RU or NA.