Quentin Defenouillere authored May 07, 2020 and hydrargyrum committed May 22, 2020

On some websites we observe 3 dates: validity_date, creation date and
execution date.
The 'date' attribute is set to the creation_date since all market orders
have one, whereas some market orders (that are still ongoing, or that
have been refused or cancelled) have no execution_date, and the date is
often used to sort the orders chronologically.