[ic] [interchange] Fix month and year adjustment wrapping issue.

[Mike Heins]

Quoting Peter (peter at pajamian.dhs.org):
> On 06/06/17 02:14, Mike Heins wrote:
> > Part of this was that I don't believe I ever defined "month" as one of
> > the items in config_to_seconds. It was never intended to be part of an
> > adjustment in the initial conception -- "m" stood for minutes.
> 
> m still stands for minutes, month requires "mo" at the least, so there
> has never been a bc issue with this.  This has been in IC since 5.7, I
> was just fixing a particular issue with it.

I understand. But because month arithmetic, on the same level that
seconds/minutes/days/weeks arithmetic works well, I didn't support it.
Nowadays I just use Date::Calc to do that stuff, but when your entire
executable size was 39K that wasn't an option.... :)

-- 
Mike Heins
End Point -- Expert Internet Consulting    http://www.endpoint.com/
phone +1.765.253.4194  <mikeh at endpoint.com>

Nature, to be commanded, must be obeyed. -- Francis Bacon