I take no credit for this. I just made a small change to add a dash in between the date and the other information. I also made a small so it works with V2.3
This contribution will create a unique Order Number, which is basically based on php's date() function.
The order number will consist of: Month, Year, Hour, Minute, Second. Basically:
date("mdY-His") = mmddyyyy-hhmmss (14 DIGITS)
You could abreviate the Year to "y" which will give mmddyyhhmmss (12 DIGITS)
** These are unique numbers that cannot be duplicated since time always goes forward. In addition, based on the order number, you can tell exactly when the order was placed!**