On the Season of Mastery Beta, the Molten Core and Onyxia raids are scheduled to close at 4:00 p.m. PDT today. (about six hours from now)
Thanks to everyone who tested the raids! We’re working on some more potential tweaks to the them, and we’re planning to do some more raid testing after a future update to the Beta build.
We’ll let you know as soon as we schedule that.