Toy,
 
Good point.  Of course it's worth mentioning 
though, that this all depends 
on the frequency!  because say with 3M, 6M or 1Y roll, there WILL be stub 
dates, both at start and end (or both) even with EOM.  And of course, the
case with stubs at start and end become a bit 
trickier.
 
To be useful in general, it would also have to 
handle the roll conventions
(ISDA terminology here) for which holiday calendars 
are needed even for 
the unadjusted (theoretical) dates; i.e. US 
Treasury, Floating Rate Notes,
Canadian Bourse MM etc.
 
James B.