At present Square does not have any holiday card options available which seems kind of surprising that they only have birthday card marketing tools. It would seem to me that holiday cards would be a no-brainer however here we are. Maybe we can suggest strongly to square an option like this be a paid or free exist for our marketing options.  

Thanks for your post @zimarm5 @IndigoSkin, I'd love to hear more about this request. Have you sent digital holiday cards for your business in the past? Did you use them to remind customers of your opening hours or was it simply a (nice) way to thank customers for their business throughout the year? 

In the meantime have you considered using the 'Send a quick update' blast campaign for this? You can customize everything in the campaign from the subject line of the email, to the images, and the message. You could edit your campaign as you see fit, e.g. remind your customers of opening hours/holiday sales — or just wish them Happy Holidays. 🎉🎄

Thanks  for the marketing options, however it really does not impact my customers like receiving a personalized holiday themed e card.  

Customers want to feel that you think of them more as a person rather than a daily sales total. Taking one day out of the year or two to tell him just thank (Happy Holidays) you for being a customer is priceless. 

A themed designed personalized e-card has more impact than a newsblast or newsletter I wish Square offered this service even if it's for an extra charge.