How to best create an On Add Validate script to include only 1 record per day?

How to best create an On Add Validate script to include only 1 record per day?

I took a stab at this but couldnt seem to figure it out.  I have remote users (on smart phones) entering data into the forms.  It seems the delay after hitting submit is quite long at times causing the user to hit it again.  This enters in duplicate forms.  With what I am doing I could limit them to one form per a given criteria.  

Here is an example of the fields:
      Home Address - Dropdown (based on another list of 60 properties)
      Notes - Simple notes field
      Time/Date stamp

How would I write the deluge script for On Add Validate that would check to make sure that I was entering only 1 form for the Home Address per day?

Thanks in advance for your help!

-S