Disable Specific Dates in Form Field

Site URL: https://viridianbar.com/cakeshop/holidaycakes

Does anyone have a solution for disabling specific dates when using the date field in a form?

For example, when someone purchases a cake from my website, a form opens up, and they type in the date they would like to pick up their cake. At the moment, they can type in any date, but would it be possible to disable certain dates such as days the shop is not open (Mondays and Tuesdays) and holidays (Christmas, Thanksgiving, New Year's Day, etc.)? This would be incredibly helpful! I saw the DatePicker on SF Digital, but I think it's a little pricey for what I need since I don't necessarily need a calendar to pop-up as my customers are all local, so the current date format is not confusing for them. 

Thank you so much for any help you can provide! 

You could disable individual dates but customers will have a poor user experience if they are required to type them in and then find out the date is unavailable and must change it again.  In contrast, a datepicker will show which dates are available and which aren’t, so that customers can only select a valid date. 

I hope this helps.