Hi Thomas, This is typically caused by a few areas working together. 1) You're on the right track with "Typical Work Hours per Work Day" in Setup. But, 2) the Assignee's schedule will also impact this, and your setting for "When multiple users are assigned to a task, use the schedule of the..." Primary Assignment / Project. If you set it to Primary Assignment, it'll go off the task owner's schedule. If you set it to Project, it'll go off the project's schedule... and this again is only for cases like "1st Review" where there are more than 1 assignees. 3) Timezone. If you're in California (PST) and the task owner (we'll say Tania for example) is in Colorado, you're most likely going to have a 1h difference in schedules. (9-5, she's going to start an hour earlier than you, and end an hour earlier than you.) If your task is set to start Mon Oct 14th at 9am based on your timezone, that's 10am her timezone. 1 day duration assumes 9am-5pm PST, her time that's 10am-5pm Day 1, and 9am-10am Day 2.(assuming typical work hour per day is 8 hours.) That's where you'll get the .## days from. I hope this helps clear things up a bit! Good luck and thanks, Dustin Martin Assigned Support Engineer Workfront