Set an Item Date Value to Another Date Value Within The Same Item (Instead of just 'Today')

The only automations available to update a Date value is to set it to ‘Today’, as a function of a dependent item, or as a function of a number column. If there were an option to automatically set a date value equal to another date value, then this could be combined with that number-column-date option. This would enable the procedural generation of reminders within a single item and the creation of an effective tracking board of to-do’s as a function of items being transferred to the board from upstream in the process.