Best Way To Sell Sessions Without Specific Date?

I am hitting a mental wall with this one. 

I need to set up a couple of black friday sales options available for online purchase. These would be for winter sessions, only available in January and February. 

Outside of special events, I generally don't have sessions available to book through the booking calendar, as my schedule changes frequently and I find it hard to continually update my availability online. Instead, clients reach out to me and we come up with a date and time that fits their needs. 

Is there a way that I can offer some sort of online purchase for a session credit, without having the client select a specific date in the calendar?

You can create a Store section (Site Content -> Add New Section -> Store) and create a standard product for them to purchase that won't  have a booking date attached to it. 

Ahhhhh! Thank you! I knew that there had to be a simple answer to this.