I did some time measurements and here is the results

[ScienceDiscoverer]

I guess many of you know that 24 ingame hours is exactly 10 minutes.
But teleport stone is actually 11 minutes 30 seconds cooldown! Odd!
So warden skill brings it to 5 min 45 seconds.

[Qelris]

They probably don't want you to use it every nights and to manage your expeditions better? It hasn't really bothered me so far.

Glad to know about 24 hours = 10mins irl though.

[ScienceDiscoverer]

Also resources respawn in 50 minutes or 5 days.

[Hermit]

Thanks for clarifying 24 hrs (NOT half a day) = 10 mins.
About the teleport stone CD: in every roguelike game it is so or even worse so that you think about everything as a precious resource. It's just tradition, it provides challenge and force you to look for alternative resources (ie: portals).