Calculating 6.5hr work days

[altja]

Ok that title sucks.

Here is what I am trying to do. I have developers that work 8 an hour day, but they don't code for 8 hours in a day. So I am trying to get the timeline to represent a 6.5 hr day. I go into project options and set hours per day at 6.5 and hours per week as 32.5. However, if I put in a task of 8 hours in it still claims that the developer is finishing the task in one day. The expected result would be that they would finish it the next day.

How should I be doing this?

I want to avoid setting the developer at (6.5/8) 81.25% because then i have to adjust that everyplace.