I want to know about how long it would take a professional to do one (1) butterfly joint with the below criteria or close to it with

no templets and no pre-cut joints. Joint would be small to medium size.

cutting the joint out w/ bandsaw or other item

marking your outline

routing 

hand chiseling the rest out/fitting

glueing and sanding down flush

I am just looking for an average time and not done in a rushed or take all day manner. Just start it & finish it in one sitting and it coming out 100% precise.

-thx