DNN 5.6.3, SQL 2008 Standard, SC 4.67

I'm using the "Show Date Field #1:" under Checkout Step 1 Setup on the cart and would like to know if it is possible for a user to hand enter the date instead of picking it from the calendar? I need a birthdate entered in this field and clicking the calendar can take to long for someone born in the '30s or '40s.

I'm already using Text Box #1 and Text Box #2 for other custom checkout fields so I can't use those.

Basically, I'm looking to capture a patient name, patient number, and patient birthdate at checkout. 

Any ideas?

Thanks for your time,
Darren