Later this week, we will open the Season of Discovery PTR for testing Blackwing Lair and Zul’Gurub.
We intend to open the raids for testing at 12:00 Noon PDT (3:00 p.m. EDT) on Friday, August 30. So that testers can get set up, we will have:

Character copy and template characters available
Most Molten Core loot available from vendors
The usual consumables and world buffs available

Please note that we want to be as flexible as possible with ending raid testing. We may need to bring the raids down at any time over the weekend, so we recommend you try to get in and test on Friday or Saturday if you plan to participate.
We’ll open feedback threads for testers’ use on Friday at Noon. See you there!