Can date pickers calculate an amount based on the dates selected?

Can I use the date pickers to do math based on the dates selected and then use Stripe to charge a credit card based on the calculation?

Yes, you can build condition which would check dates. Please see below:

Guides: 

How-to-Insert-Text-or-Calculation-into-a-Field-Using-Conditional-Logic

How-to-Perform-Form-Calculation-Using-a-Widget

To pass calculated total to Stripe field, please review this guide: How-to-Pass-a-Calculation-to-a-Payment-Field

We will be glad to assist if you need more help, just let us know.