Multiple project arms with different anchor dates. Best way to solve?

Hello! We use excel to do project planning. Within a single project, we have multiple arms that follow the same event intervals but oriented to different anchor dates. Example attached

Currently, we create a new schedule for every Project Arm in order to project the proper event dates, but I'm sure there is a more efficient way wherein the Project Schedule would be created once, the Anchor Date for each Project Arm would be entered, and the system would automatically produce the event schedule for that particular Project Arm by referencing the Project Schedule

So, what's the best way to approach this problem? I've done VBA in the past but not really in connection to excel, and I'm not really sure that's even the best way to go about solving this. Any advice to get me in the right direction would be much much much appreciated.