Transactions have both a @value-date (against the value element), and a transaction-date which should have an@iso-date element, but doesn't always (with a date sometimes found in the value of transaction).

Knowing what to do when an iso-date is missing is important (e.g.. should I try and turn the value of transaction-date/node() into a date using a string-to-date function? should I fall back on @value-date (not a good idea - this is only there for currency conversion), or should I use the activity dates?)