To the whole account, not per kitchen — but note the Cut-off Timer page actually holds two independent weekday schedules, one under the Meal Prep tab and one under the Retail tab, and each of those applies account-wide (the settings are excluded from per-kitchen overrides). The account-wide closing job locks the shared delivery dates for every kitchen at once. If two kitchens need different cut-offs, a practical workaround is to give them different fulfilment weekdays in Kitchen Locations so each weekday's cut-off window lines up with the kitchen delivering on it. Grab & Go is the one exception, with its own per-location cut-off engine.