Content Calendar that works?

Has anyone really had success with running a content calendar for marketing and strategic communications?

Do you have a specific format or platform you use to effectively manage a content calendar?

I have tried so many different formats and approaches and ultimately planning any real length out tends to be a fool's errand. Circumstances change and planned comms aren't relevant, or the organization is not ready with information or details you need to really be planful.

Nearly every client or organization I work with wants or expects a content or communications calendar and I always dread that part of the role because it seems like unnecessary administrative work.

What's your experience?