At the end of season three I will look at the highest level key timed across all dungeons. Then I will look at each dungeon. If that dungeon was successfully timed at that level then that dungeon will resolve yes, otherwise no.

For example, at the time of creation the highest timed key is 29. Both Black Rock Hold and Atal'Dazar have been timed at 29. So both BRH and AD would resolve YES, and the rest would resolve NO.

I will be using the raider.io public timed rankings leaderboard. So no tournament realm/great push entries will be allowed.

This market will resolve when season 3 comes to an end. This is when you will no longer be eligible to complete season awards (mount, etc). That season end date currently unknown. Once it is known this question will be update.
/Nikos/wow-in-what-month-will-season-3-end