I would like to be able to create date ranges based on custom dates so that I can build calendar views that are not based on start/due date fields.

My use case is that I'd like a calendar view showing when campaigns are LIVE, so we can easily see them, see what campaigns overlap, etc.

Right now, you can create this view, but only based on start/due date fields, but these dates are not always the "campaign live dates", they are changing due dates based on the stage that the project is at. Aka start date = when work started on the project, and due date = when everything (including post live tasks) conclude, not the actual dates of the campaign.