There should be two different date boxes when entering bills to be paid.  A bill from a vendor could have a date of 12/1 but the service was really in Nov, so I want to post it in November, but the post date is driven by the "bill date", which is very frustrating.  Why can't there be an 'invoice date" and a "posting date", with a default to the invoice date unless something is entered?  This is a basic feature of any accounting system and would be very easy to fix!