There's a lot of upkeep and maintenance that we need to do with our data centers and network infrastructure globally. Over the years we have been performing maintenance work in unscheduled but still repetitive time periods and it was quite inconvenient in preparation and management, as well as in advanced player messaging. We are leveling-up the maintenance process by establishing scheduled and recurring maintenance windows which will let us perform the necessary work on a regular cadence.
This new regular maintenance window will be set every other week on Wednesday mornings European time. This day will be the opposite Wednesday of the patch and it can shift if the patch needs to be re-scheduled. Depending on the scope of required work, the player impact can range from none, to ranked disabled due to expected reconnects, to full platform downtime. This maintenance window might not have definite downtime, and will only be utilized if specific work risks Player impact. Obviously when it's possible, we plan on doing maintenance without interrupting the players.
Having one standard time period for service impacting maintenance will both add predictability and help us reduce negative player impact. Here are the schedules for all EU shards, which basically are identical to patch times:
EUNE - Start time (GMT) - 02:00am; Ranked queues disabled: 00:30am
EUW - Start time (GMT) - 04:00am; Ranked queues disabled: 02:30am
Maintenance duration will vary depending on the scope of works to be performed. We will do our best to give you a rough estimate each time, however the work load timeline is sometimes hard to predict and our estimates might be inaccurate. The usual network or hardware works should take from 2 to 4 hours each maintenance window.