"Say you are an institution founded in 1920. It is safe to assume that
you are not sitting on any information dated from before then; and so,
in the double-digit date-recording system, "20" becomes your pivot year.
This means that data containing a two-digit year between "00-20" will
be treated as post-2000, while years between 20-99 will be interpreted
as referring to the previous century. "