Expand my Community achievements bar.

Do you have questions about the migration to Adobe Business Platform? Come join our upcoming coffee break and ask away!

How to create a project template that can calculate dates forwards AND backwards?


Level 1

I am attempting to create a project-plan template that will ask the project manager for a 'product go-live' date, and it will then auto-populate dates for tasks that occur before this event (such as a kick-off call and product setup), but also auto-populate the dates for certain tasks that will happen after this date (such as monitoring the product & handing it off to a product owner). I'd like users to have flexibility to edit the length of the post go-live phase.



The Project Manager determined beforehand that the Go live date is 8/1/24. Therefore:

  1. Kick off call should occur 7/1/24
  2. Product setup should start by 7/8/24
  3. Go Live is 8/1/24
  4. Monitoring product quality for the next 2-3 weeks (Flexible).
  5. transition product to product owner after step 4 is complete.


If I use the 'projected completion date', then all tasks would be calculated based on the last task, which no longer gives users the flexibility to edit the length of this post go-live phase.


Does anyone have any suggestions for how I could create a template that auto-calculates dates based on a specific date that happens mid-way through the project?



Topics help categorize Community content and increase your ability to discover relevant content.

1 Accepted Solution


Correct answer by
Level 10

Hi @SanderDe,


I invite you to review our Get a Handle on Project Start Dates blog post, which might give you some ideas on how to use templates to "back into" the right Project Start Date.




View solution in original post

6 Replies


Correct answer by
Level 10

Hi @SanderDe,


I invite you to review our Get a Handle on Project Start Dates blog post, which might give you some ideas on how to use templates to "back into" the right Project Start Date.





Level 5

Would something like this work?  The project schedule mode is Start Date (with the project start being well in advance of whenever a first task would need to start).

go live schedule.png

The Go Live task has a Fixed Dates constraint--with preceding tasks having the As Late As Possible constraint and subsequent tasks having the As Soon As Possible constraint (I used 10/1 for a go-live date in this example instead of 8/1 because we have some summer half-days in our schedule that made things look a little wonky).

I manually set the date for the Go Live task, but you could possibly have that value as a custom field which Fusion then uses to set the date.





Level 2

This is how we do it as well.  We have two dates in the "middle" of our projects that we set to fixed dates, and then the preceding and subsequent tasks calculate from those.  


Level 9



this seems to be an absolute game change for me! What a coincidence that this thread has just appeared here. In the last days I was working on a solution for the following use case:


We do know the date of 1st sale of a new product, so like the go-live date. Based on that all tasks should end leadtime in days (leadDays) before the 1st sale date and start time for preparation in days (prepDays) before the start task's end date. leadDays and prepDays are specific for each task and are saved in two custom fields on each task.


Calculations for each task:

planned end date = 1stSaleDate - leadDays

planned start date = planned end date - prepDays


So I played around using task constraints and made different calculations using calculated fields at first and directly in Fusion later.


As we needed to visualise the 1st sale date in the Gantt chart, I created a "dummy" task with the name "1st sale", to which the milestone "1st Sale" is assigned. This task starts and ends on the same day. Now in the Gantt chart the first sale date is visible as a diamond.


To make the whole thing more dynamic, I wanted to have the possibility to be able to let the user change the 1st sale date (e.g. by moving it within the Gantt chart) and let all other task's dates automatically be recalculated.

This recalculation is done by Fusion triggered by a watch event. The main disadvantage here is the fact, that the users have to reload the page to see the new dates and that the calculation takes a couple of seconds.



Although it is already saturday, my brain is still in "Workfront mode", so I came up with the idea to try around with the predecessor logic and considering the 1stSale-task as the master task.


Finally I found this thread and was totally thrilled, when I adapted your solution on my setup.


I'm pretty sure the answer is no, but it might not be possible to use custom fields as variables in the predecessor-values for the lag time, right? Although possibly I can do that using Fusion with the help of this thread.


Thanks again!




Hi Lars,


Rather than custom data and Fusion (for the reasons you’ve cited), I’d suggest you:


  • add an ALAP “dummy 2” task called “1st sale prep days”
  • tie all preds that were pointed to the “1st sale” task to “1st sale prep days” instead
  • tie “1st sale prep days” to “1st sale” finish-to-start
  • remove all lags on both
  • set the duration of “1st sale prep days” as appropriate


By doing so, as per animated gif in my blog post above, end users can then easily see and adjust the prep days using the native Gantt Chart interactively.