As for holidays... aka "Holy Days".... I work for Catholic schools where,
contrary to what people outside of them might think, the holiday themes aren't
promoted unless it's done in a way that's liturgically correct. There's no
Santa Claus visiting school at Christmas time... no poinsettas...etc. etc.
Easter brings no bunnies... it's a sober, contemplative time. St. Patrick's
Day IS a big one though- with elves and leprachaun traps and green rolling
hillsides to think about.
The thing about subject matter to me is that it's all in the handling. Kids
are more enamored of the seasons than many adults... they love the holidays
so if a teacher wants the students' interest it isn't all bad to have some
seasonal/holiday focus. The secular celebration of "Holy Days" is haphazard
in the US. The cultural traditions of every country I know of include lots of
celebration oriented artwork.
The more cerebral and emotional concerns of contemporary art seem to attempt
to detach art from society... and reinforce philosophical distance from our
ancestry and from the "old" locus of religion. Of course in public schools
it's illegal to be overtly concerned with the history of most holidays...
because religion is there. Such a big no-no.