There seems to be this: Create 'Specific date' or 'Contact date property' contact-based workflows
but it has a MAJOR Fault - you can only send the emails in the workflow in your timezone. Even their example this is a blooper - they use the idea of a birthday to send a coupon but as you can only send this in your timezone and if you have global clients like I do then I could very well be sending them something that arrives not on their birthday but the day after or before!
I wish this came with the ability to set local time zones as well.