At room temperature the chocolate should set within 5 to 10 minutes however sometimes depending on the humidity levels in the room it could take 15 to 20 minutes for the chocolate to fully set.
I've always had my chocolate set up within 10 minutes.
The thicker the layer of chocolate that you're setting up the longer it will take for the chocolate to set so a thinner layer of chocolate should set within 5 to 10 minutes.
And a thicker layer of chocolate may take as long as 15 to 20 minutes to fully set and be read at room temperature.
Still it doesn't take very long for chocolate to set up at room temperature.