Overview
Salesforce has issues with dashes when dates are submitted via the Salesforce connector. A simple formula will allow you to automatically convert the date from MM-DD-YYYY to MM/DD/YYYY.
Resolution
Use the following formula in your date mapping to automatically convert your date field:
@IF(@CONTAINS("-",%%tfa_xxx%%),@SUBSTITUTE(%%tfa_xxx%%,"-","/"),%%tfa_xxx%%)Replace tfa_xxx with the field alias for the date field from your form.