I have multiple tasks that have different durations that I want to start at different times from a go live date, i.e. finish date for an entire project.

For example: Project must finish on 01 Dec 2019. Task 1, duration 10 days, should start 20 days before 01 Dec 2019. Task 2, duration 20 days, should start 50 days before 01 Dec 2019, etc.

How can I set this up? I would like to be able to amend the finish date (if needed) and have the dates for all tasks recalculate.

  • Do the individual tasks have dependencies between themselves? so for example, must Task 1 complete before Task 2 or Task 3? And do you want to be able to flex the durations of the individual tasks? So in your example, could Task 1's duration change to 12 days, and if so, do you need it to start a further 2 days earlier, or finish two days later? Unless we understand the planning constraints, it is hard to give a definitive answer.
    – Iain9688
    Commented Feb 18, 2020 at 8:33

1 Answer 1


This is what's called a backward pass. You want to calculate the task dates based on a fixed project finish date. To do this:

  • Create your tasks and link them together.
  • For the last task, set a constraint type of Must Finish On and set the go-live date.
  • For all other tasks, set a constraint type of As Late As Possible.

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