Is there a way for the date field to be left blank?  It defaults to "todays" date.  
 
We post labor the following day,  and ever so often we will forget to use "yesterday's" date and then have to enter a negative.  
 
I may have missed a default setting.

BTW, if it WAS set to 00/00/00 I learned a trick from one of my employees a few months ago (this works regardless of what the date is, but would work really well for your application). The "+" and "-" keys add and subract days from the displayed date. If it's 00/00/00 "-" puts in yesterday.