Turnitin have informed us of scheduled maintenance on July 26th, as follows:
“The Turnitin service may be unavailable during a scheduled maintenance period on Saturday, July 26th, 2014, from 9 AM to 9 PM U.S. Pacific Time (click for local time). We will be making significant upgrades to improve capacity and scalability as our service utilization grows. An announcement will appear for users within Turnitin in advance of when the system will be unavailable for this scheduled maintenance. This maintenance will affect Turnitin and TurnitinUK users. Instructors are encouraged to modify assignment due dates either before or at least several hours after the scheduled maintenance window.”
Turnitin also provides updates via the Turnitin System Status page or via Twitter at @TurnitinStatus.