From: Saašha Metsärantala
> > why do we even need yearMonth, when month alone would be sufficient.
> I should have clarified my aim with that. In one way, it would be
> easier to only use month, but for long periods, I thought it would be
> easier to read /P123Y than /P1476M. As you suggest, it rises the
> question of c14n but this may be solved by a reformulation such as:
> monthsDuration = oneThru11 "M"
Ok, I've made this change.