EU Shards will be down for four hours.

Amanda 'Amary' Fry posted on the official forums:

The EU region shards will be coming down tomorrow to pick up both a Hammerknell-related hotfix as well as some wargroup reconfigurations as announced here:  http://forums.riftgame.com/showthrea...configurations

The downtime will begin at 1:00am GMT 29/7/11 and we've set aside a 4-hour downtime window to complete the wargroup changes, though we hope to have things wrapped up faster than that.

Here's our time zone converter to help you plan.  Watch this space for patch notes when they beome available.