"Have you told your mum about Thursday?" is a question that can start an argument in almost any house. Thursday being the day she's doing pickup, which was agreed on the phone three weeks ago, and which has since moved to Wednesday.
Grandparents and childminders are often the most important people in the week's logistics, and the least connected to wherever the plan actually lives.
They don't need the whole diary
The instinct is to give everyone access to everything. Resist it. A grandparent who opens a shared calendar and sees forty entries (swimming, work calls, a dentist, the bin collection) will close it and never open it again.
What they need is the handful of things that involve them: the days they're collecting, the school play they're coming to, the week you're away. Everything else is noise.
“Grandparents don't need the whole diary. They need the three things this week that involve them.”
Meet them where they already are
Some grandparents love a new app. Many don't, and that's fine. Work out how they already get information, and use that.
If they use a smartphone calendar, share a single calendar with them, one that only holds the things they're part of. Google and Apple calendars both let you invite someone to one calendar without showing them the rest.
If they live in WhatsApp, a short message on a Sunday evening does the job: "This week: Wednesday pickup is yours, 3.15. Saturday we're at Leo's party, so no need to come over." One message a week beats ten scattered ones.
If they prefer paper, print the week. Honestly. A sheet on their fridge with their days circled is more reliable than any app they don't open.
Make changes impossible to miss
The plan changing is when things go wrong. Pickup moves from Thursday to Wednesday and the message about it is buried under photos from the weekend.
A simple rule helps: any change to something a grandparent is part of gets its own message, sent the day it changes, starting with the day. "WEDNESDAY now, not Thursday." Nobody has to scroll to find it.
Say thank you in the plan
This one's small, but it matters. If Grandad does every Tuesday pickup, put it in the calendar as his, with his name on it. It's easy for regular help to become invisible, and seeing it written down is a small way of saying it counts.
The short version
Decide what they actually need to see. Send it the way they already read things. Flag changes loudly. That's all of it.
If you'd like one shared calendar for the whole house, that's what Noa is for. But a Sunday message and a printed sheet will get you most of the way there.