The text box labelled Opening Hours (up to 200 characters) is a free note attached to the route – for example "Deliveries between 4pm and 8pm". It is not admin-only: it's shown to the customer on the checkout delivery screen and in the order-confirmation email whenever their order uses this route, and it's also shown to staff in the admin order screens. The structured Opening time - Closing time pickers below it are what actually drive time-slot validation.