I work in project management so I live it daily.
I created a template of tasks and assigned days prior and post an install(event) date. I had a field designate the tasks are for template purposes in the task table and made my automation copy those. I have to have a relationship between the events and the tasks to get the event date or in your case it would be the project start date. Then I have in tasks the formula for the task due date which helps when the start date changes. Below is my 'some complicated' formula to offset the weekends.
If([Days Prior]>0,WeekdayAdd([Event Date], -1*[Days Prior]),
If([Days Post]>0,WeekdayAdd([Event Date], [Days Post]),
[Event Date]))
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Jason Johnson
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