Duration
The Duration field is populated when you import data from MS Project, and it displays the amount of time in days that it will take to complete the current task. A day is 24 hours. So for example, 1 day is 24 hours, and .33 days would be 8 hours.
A day is considered to be 24 hours even if you have a Project Calendar set within MS Project with an 8-hour working day. The conversion to a 24-hour day is done when you import the data from MS Project.