Every delivery date carries two flags that the menu calendar colours reflect:

• Open - customers can order; shows green when the date has meals.
• Closed / In Progress (orange) - ordering is stopped. Dates close automatically when the cut-off passes (the nightly close routine) or when you close them by hand on the dashboard. Admins can still edit the menu, and it can be reopened.
• Finished (red) - marked finished after production/delivery. Also editable by admins, and cloning skips both closed and finished dates as targets (Catering excepted); customers never see either.

Menu building is independent of these flags: you can prepare menus weeks ahead while the dates are still open, and closing a date does not delete its menu. See the dashboard article for opening/closing and the cut-off article for the automatic timing.