when we cross the DST boundary all (well, most) times will be shifted by an
hour, due to everything being recorded in GMT and timezone translation referring
only to current offset by locale, not future offset.  if anyone has set up a
test or workbook enablement across the line, they may find it shifted when the
boundary is passed.

this should be handled more gracefully.  at the very least all displayed times
could include the timezone (which includes DST indication) in which they apply,
or perhaps the offset from GMT.  perhaps something else would work more intuitively.