Rick, very very astute

Not really... I once proposed a first such-and-such day in a month solution
using the +7/-4 adjustment and found it produced incorrect results when
tested against another solution that used the +8/-5 adjustment... so I am
kind of sensitive to its usage and I notice its use more readily because of
that. However, there may be a problem with the +8/-5 adjustment method also
(see my other post in this thread)... when I get the time to look into it, I
will try and prove or disprove its usage in the simple first such-and-such
situation (I can't be sure it is a general problem with the method or just
one that cropped up because of the additional requirements from the OP's
request).

Rick