You update a shared document after changing the schedule. Someone who relies on the old date does not see the edit and continues preparing for it.
Identify who is affected by the change and tell them directly through a suitable channel. State the previous arrangement, the new proposal and the reason where it helps. Keep private details out of channels that do not need them.
Ask for the needed agreement
If the change requires another person's commitment, check whether it works for them. Updating a calendar does not obtain consent to a different time or cost. Confirm the final arrangement once the affected people have answered.
Remove or mark obsolete instructions where others might still find them. If the change is uncertain, label it as proposed and say when a decision is expected. A useful message lets people distinguish what has been decided from what they are being asked to consider, so they can adapt their own plans with the right information.
