Selecting earliest date among all related tasks

You can do that with 2 rollup fields in your Projects table.

Each rollup field would point to a date field in the Tasks table, and you would use one of these formulas:

MIN(values)
or
MAX(values)

- ScottWorld, Expert Airtable Consultant

Thank you for the response! I tried creating a "rollup" date field in the Projects grid, and then did rollup for all Start Dates in the Tasks grid. The trouble I ran into is that when I went to set a condition for which dates to rollup, I only saw a way to select a specific Project as the condition. In this case I have multiple Projects and need the rollup to be variable to each Project name. Am I missing a feature or is there a workaround? 

This looks correct! I was able to click into the base, but when I click the field to see how it's setup I can only "copy field URL". 

Yeap you'll need to duplicate the base to your own workspace!  To do that, click on the base name, followed by the three dots, then 'Duplicate base':

Thank you for all the help!