Mirror a specific item date column, to a specific subitem date column


I have a board that’s generating some work back dates so I have several date columns. On these items I have some subitems that have some cooresponding tasks associated with the work back dates. I want to mirror the dates shown on the parent item down to specific subitems. I have found multiple paths to mirror a single parent item date down to every subitem, but I need it to be more targetted than that.

TLDR, if I have parent item X, Y, and Z; I need those dates to mirror to the respective subitems X, Y, and Z.

Update, I’ve restructured and handled the tasks and associated dates together all as subitems. I have gotten very close to what I need, but my challenge now is that the app I’m using to manipulate the subitem dates doesn’t allow me to offset negatively, only positively. Being a work back schedule though, I want to set a date in the parent item that then adjusts the work back dates in all the subitems based on work back parameters I have set.

The below image hopefully helps visualize things. Creating the item will auto-generate my subitems and set the “Workback days” for each. Then setting the parent “Target Launch Date” will generate the subitem “Workback Date”. The issue is now generating the Days as negative. I am using the “Subitem Automations” app for these automations.

I continue to iterate…

My approach now is I am copying the “Target Launch Date” from the parent item, down to each Subitem, then using a formula to subtract the “Workback Days” in order to make my workback schedule for each Subitem. The challenge now is I can’t convert this formula date to fill in a the “Workback Date” column, which in turn would allow me to view the dates on a Gantt chart.

Functionally this does what I need, but I really need to view this data on a chart. Any insight would be appreciated!

Quick update, I was able to achieve things using the app Autoboost! It allowed me to run the formula within Monday to subtract days from a Date, and set that new date in a subitem column.