Nick,
It sounds like your data has been pre-pivoted. I'll give an example
In a transaction table, you'd have transaction id, transaction type, transaction date and transaction amount.
In your version, you've got transaction id, transaction amount and multiple date columns all representing the different transaction types - sales date, delivery date, return date, refund date, restock date, etc.
Is there any way that you can get back to the pre-pivoted date?