Timeline auto populate / automation

Hi monday.com Community!

I have been struggling to find solution on timeline set-up as I’m not familiar with integrating with app into monday.com.

As shown on the image, I have a quick question about the timeline.

Let’s assume we have two tasks, A and B:

Task A needs to be completed 60 days after the hotel opens.

Task B needs to be completed 30 days before the hotel opens.

Is it possible to automate this using the duration column (such that dates are auto populated without having to select manually), or do you have any alternative suggestions for how we can manage these timelines?

I really need step by step guideline on this.

Thank you so much in advance!