Accounting standard for "one month ago"

Christopher Browne
Fri, 11 Aug 2000 00:01:34 -0500

On Fri, 11 Aug 2000 12:27:05 +1000, the world broke into rejoicing as
Robert Graham Merkel <>  said:
> As previously reported, I'm adding a new type of option for relative
> dates.  I'd like to add a relative date for "one month ago".  My
> simplistic definition for "one month ago" on 
> m/d/yy is (m-1/d/yy) but this
> of course poses a slight problem on, say, the 31st of May.
> What should we do here, or should I avoid the problem entirely and use
> "30 days ago" instead?

Unfortunately, it's inherently a bit ambiguous.

The day "a month back" from July 31st should be June 30th.

And the day "a month back" from June 30th should be May 31, and one
month ahead should go to July 31st.

The other date that provides a touch of additional confusion is July 30th.
Should a month back represent...  June 30th?  Or is that June 29th?
Actually, I'd go with June 30th.

My inclination is to treat the last day of the month in a "sticky"
manner; a month back is always the last day of the month, regardless
of number.  The 30th of a month with 31 days would move to the 30th of
the previous month.  And, perhaps, "refuse to be sticky." 

Pretty bizarre; dates are _not_ trivial to play with...
-- - <>
If there's one thing I can't stand, it's intolerance.