60 Minute Time Limit on New Dungeons

[Physic]

Time limit is fine. 20 minute prep time, hour long content, all in all it's nice.
Time limit is also meaningless if you don't know the entry limitations.
If it's once every 24 or 36 hours, an hour is fine.

Im leaning toward a fairly difficult endeavor with many different paths that you can repeat a lot in a short time frame, but its hard to beat.
Id go with a money or item requiremt as the limiter. thinking back on it, the long recast timers on certain events didnt add much to them for me.