SW:TOR Scheduled Maintenance: Update 2.9: Galactic Strongholds (Early Access)
I'm replicating the announcement here, as I had a little trouble finding it.
Original Maintenance Announcement on official forums
On August 19th, all game servers, SWTOR.com, and the launcher will be unavailable while we perform scheduled maintenance. Game Update 2.9: Galactic Strongholds will be implemented during this downtime. Details are as follows:
Date: Tuesday, August 19th, 2014
Duration: 5 hours
Time: 2AM PDT (9AM GMT) - 7AM PDT (2PM GMT)
During maintenance, all updates and additional information will be posted on our Twitter account.
Original Maintenance Announcement on official forums