We are planning to deploy a fix to resolve an issue where citadel vulnerability timers were unable to be changed. This fix is not being deployed immediately so as to give players advance warning of a non-standard timing of a vulnerability window change.

This change will be deployed with the May release on Tuesday, May 31 2016, during downtime (11:00UTC). Once this fix has been deployed, any vulnerability timer changed before 00:00UTC on Monday, May 30 2016, will take immediate effect during that downtime deployment. Any changes made to vulnerability timers after 00:00UTC on Monday, May 30 2016, will take effect at the regular time of 00:00UTC on Monday, June 6 2016.

More details on Citadel vulnerability windows can be found in this help center article.

For further discussion or questions about this topic, please see this forum thread.