Board Thread:Game Discussions/@comment-213.164.6.97-20150119180735/@comment-129.255.228.52-20150120190353

Last time it was about a week, maybe a little over a week between the end of one heroic mode and the beginning of the other.

And sorry wiki contributor, not only did it say it in the FAQ, but it also says it in the pop up if you click on the event in the announcements. There really isn't anything you can do since it was stated in a few places. Just learn from it for next time.