If your website has an Order Delivery Date Picker option you can set certain delivery dates of the week or block certain days (ie weekends) along with public holidays.

From the Dashboard:

 - Order Delivery Date

As show above, Monday to Friday have been set as delivery dates for customers to select.

Please ensure "Enable Delivery Date Capture on Checkout Page" is Enabled

To block out public holidays or certain dates:

 - select Holidays tab

 - enter Holiday name
 - select date (or date range)

 - if holiday recurring on same date each year please tick (ie Christmas, New Year)

 - Once complete click Save

(customers will not be able to select this delivery date at checkout)

Checkout Date Picker Tool

The date picker tool at checkout will now block no delivery dates (ie weekends and public holidays)