Default Invoice Date for Three Way Match

Is there a processing option or some other configuration setting that controls the default Invoice Date when you add a Voucher during the three way matching process?  Currenlty when I click ADD the new voucher begins with both the G/L Date and Invoice Date the same date (the current day).

Can I change the default inovice to be blank to remind the user to enter the suppliers invoice date?

Thanks for any help.