Do shared calendars actually reduce family mental load?

I’m working on Shareday, a family planner built around a simple question: why does family planning still so often become one person’s invisible job?

Shared calendars help with dates, but in real family life the hard part is usually broader: who owns the task, what needs to be bought, who needs to be reminded, what changed in the plan, and whether everyone actually saw it.

For parents, partners, and people building productivity tools here: what has worked best in your household or product?

- One shared calendar for everyone?

- Separate calendars synced together?

- Assigned tasks and shopping lists?

- Chat around each plan?

- Something completely different?

I’m especially curious where shared calendars stop being enough and where families need a more complete planning space.