That's strange - I'd expect them to duplicate along with the base.  Attaching screen grabs of the automation setup.Step 1 Step 2 Step 3  Step 3 detail  Step 4  Step 4 detail 

It sounds like you have everything set up and just need to create the automation that will populate that currently empty linked field.  The example is set to trigger whenever you change something in the Projects (Main) table.  Let me know if you have...

Hi CharlieB,I used a formula generated by Kuovonne https://community.airtable.com/t5/formulas/return-months-from-start-end-dates/td-p/35722 and extended it to cover projects up to eight months in length.  This generates a list of all the months in th...