Integrate holiday dates

I have a project schedule to which I want to add the developer holiday dates.

If a holiday date falls during a development phase, I want the duration of the task to be extended by as many days off.

For exemple :

Task 1 04/01/2022 to 04/14/2022

Holidays Dates 04/11/2022 to 04/18/2022

Task 1 must therefore end on 22/04/2022

How to do that?

You could create a formula column to get the duration of a timeline:

WORKDAYS({timeline#End},{timeline#Start})

and then use an automation like

When formula column changes push date by number of days

the number of days could be picked from the formula column. Not sure whether all of this is really supported. But it is worth a try.