The TT documentation says ...
in reply to Re: Sorting Template Toolkit Array of Hashrefs
in thread Sorting Template Toolkit Array of Hashrefs
"When an item in the list is a hash reference, the search key will be used to retrieve a value from the hash which will then be used as the comparison value".
Since row.agendas.0.agendaDate retrieves the value inside the FOREACH loop, it seems reasonable that it would retrieve the value for the sort comparison, but alas it's not doing that. :(
"Its not how hard you work, its how much you get done."