In Microsoft Project 2010, you can create a custom calendar to set your day as something different than the default 8 hours per day. In this example, I changed the working time to 7.5 hours per day.
So far, no problem. However, look what happens when you view the Resource Usage Tab for the same task:
That’s not what I want - I said 7.5 hours per day is the working time! It should be 7.5 hours per day, not 8 hours for the first 4 days and 5.5 hours for the fifth day.