Honestly, it's been all over the map in recent weeks. I made my reservations at 60 days out and they got released at 3am pst/6am est and I was able to grab all the times and options I wanted.
Some other days, there was a delay in the release times and they didn't show up till 8am pst/11am est and I was refreshing every 15 minutes or so to see when they would finally drop.
Other days, there have been delays and they were released either at 57 or 58 days out, it's really been inconsistent. Plus with more sit down restaurant options being released and added capacity, the release times/dates have been all over the map.
Personally, I'd start looking at 3am pst at 60 days out and if you can't find the options you're looking for, keep checking every once and awhile. Also don't look in the Breakfast\Lunch\Dinner buckets and instead look hour by hour. It's a longer process but some of the options I wanted (Oga's for example) didn't show up as Breakfast\Lunch\Dinner time slots but when I searched hour by hour, I was able to snag a 12:45pm time at Oga's on the day we visit, which is perfect for us, since that's an hour after our lunch.
Good Luck!