Change start date, update entire project

how can I update the star date of the project (first task) and the all tasks are shifted according to the new start date?


Project > Properties > Calendar > Move project start date

Thanks! It sure is simple!

This is only partly working for me on OSX, Mojave.

It seems to move the dates of all of the tasks, but the initial start date remains the same.

New start date says September 13, 2021, but it comes up as week 41 in the project.

Please clarify what do you mean when you say “but the initial start date remains the same”. There is no such thing as “project start” in GanttProject. It starts when its first task starts. If “it seems to move the dates of all of the tasks” then it moves the first task start date as well.

Sure. This has been confounding to me as well. Check this image out:

See how the tasks all start on Sept 13th, but it comes up as week 38?

So, the start date has changed fine, and you’re concerned about the week number? Please read the FAQ.

Well, maybe I’m misunderstanding you, but with the first task beginning on 9/13/21, I would expect Week 1 to be (around) 9/12/21 and not Week 38 (as if the project still had the original start date of three years ago.)

Thank you, very much, by the way, for your help, Dmitry.

You see the numbers of weeks of year, not weeks of project.

Okay. Perfect. Seemed like I needed to slide the weeks in the display to the correct position and re-save. Peace. –Mike