Payment Date column in Write Check should be the same as the Date Paid in Pay Bills form.
For example, you created a Bill and changed the Due Date (it should not be the same as the Bill Date). Bill date is 4/3/2008 and the Due Date is 4/30/2008.
Then you paid the bill using advance date payment, Date Paid is 4/4/2008.
This is now the Check created. In Write Check, Voucher Check Detail and Voucher Check Detail Split reports, Payment Date column should display the exact date when the payment was made.