The school year does not arrive as a calendar. It arrives as a PDF, three emails, a portal login, a paper letter in a backpack, and a parents' chat that will produce four hundred messages by October.
Do the transcription once, early
Block an hour before term starts and move every fixed date into one place: term dates, breaks, in-service days, picture day, parents' evenings, and the sports fixtures if they exist yet. It is a dull hour. It replaces about thirty separate moments of "wait, is that tomorrow".
Then decide who owns each recurring thing
Pickup, homework oversight, sports kit, lunch money, reading log. Each of these is a small recurring load, and the reason they all end up with one parent is that they were never explicitly assigned — they were absorbed by whoever noticed them first, in the first week, forever.
The group chat is not a schedule. It is thirty people hoping somebody else wrote it down.