Duration
Scheduling Terms
Reviewed by forProject Technology - updated Sep 2026
Quick definition: Duration is the estimated time — in working days or portions of a day — needed to complete a task, based on a specific working calendar.
Duration measures time from a task's start to its finish against a defined Working Calendar of working and non-working days, not the amount of labor effort required. A task can have a long duration but relatively little actual work effort, or the reverse.
Why it matters
Getting Duration right is fundamental to building a credible schedule, since it drives calculated dates, float, and ultimately the Critical Path. Confusing duration with labor effort is a common scheduling mistake that can throw off an entire schedule.
Also known as
N/A
Used in
Critical Path Method (CPM) calculations; Duration Percent Complete
FAQ
Is Duration the same as the amount of work required for a task?
No — Duration is time measured on the Working Calendar (in working days), while work (labor effort) is the actual amount of effort required (in labor hours, for example). A task can have a long duration with little effort, or vice versa.
What Working Calendar is Duration measured against?
A specific working calendar defined for the project or task or resource, which distinguishes working days from non-working days such as weekends and holidays.
Definition maintained by forProject Technology.
© 2026 forProject Technology, Inc.
© 2026 forProject Technology, Inc.
