Late Start Date (LS)
Scheduling Terms
Reviewed by forProject Technology - updated Sep 2026
Quick definition: The Late Start Date is the latest a task can start without delaying the project: its Late Finish Date less the task's Duration across its working calendar.
The Late Start Date is the Late Finish Date less the task's Duration, counted in working days. Comparing it to the task's Early Start Date shows how much float, or scheduling flexibility, that task has.
Why it matters
Knowing the Late Start Date tells a project team exactly how long they can wait to begin a task before it starts putting the project's finish date at risk. That's useful for prioritizing where attention and resources go first.
Also known as
N/A
Used in
Critical Path Analysis; Total Float calculations
See also
FAQ
How is the Late Start Date calculated?
By taking the task's Late Finish Date and subtracting its duration.
Is the Late Start Date the same as the Early Start Date for a Critical Path task?
Typically yes — on the Critical Path, a task's early and late dates are usually the same, since there's no float to work with.
Definition maintained by forProject Technology.
© 2026 forProject Technology, Inc.
© 2026 forProject Technology, Inc.
