Travel Authorization Accounting Date - How to Move TA Between Months

We are having trouble with Travel Authorizations that are not used in the same month that they are recorded.  When a month is closed our procedure is to update the accounting date on Expense Reports to the new fiscal month.  The Travel Authorization does not expose the Accounting Date so the result is that agencies need to cancel the Travel Authorization and set up a new one in the current month.   This also has resulted in the majority of our Business Units choosing not to use the TA because of the hassle.

Is there something that we aren't doing correctly that is causing us the problem?  If not, could the Accounting Date on the TA be editable so that we can move them between months?