As well as been able to prevent customers from selecting specific days of the week for shipping, you can also blackout specific dates of the year. This is useful if you don't provide shipping over national holidays. Follow the guide below to learn how to prevent customers from selecting New Years Day for shipping.
Click Settings from the main menu
Scroll down to the Shipping section and locate the Blackout date controls
Click the field labelled Enter new blackout date to reveal a calendar
Select New Years Day from the calendar
Click the Add blackout date button