I tried your suggestion without success. To flesh is out, this is what I did.
- Created a new mmp
- In that mmp, I create a new Calendar as a copy of "24 Hours" named "Operations" using the Changing Working Time window
- Made minor customization to "Operations" in the form of an exception day for Christmas
- Saved the changes by clicking "OK"
- Entered a few tasks with the default calendar "Standard (Project Calendar)"
- Entered a few tasks with the default calendar "Standard (Project Calendar)" then changed the default calendar to my "Operations" calendar
- Entered the duration of the tasks with the "Operations" calendar
This brought the same results. A three day task entered using the "Operation" calendar is represented by a Gantt chart bar of one day despite the Duration column for the task indicating three days. What is likely a simple solution does not appear to fit my definition of "intuitive". All I need is someone to set me on the righteous path of Microsoft Project intuition. I am not comfortable investing more time on this project with this software until I can resolve the seemingly basic problem.