def _have_cache_for_date(self, dt):
for p in self.projects:<EOL><INDENT>if self.cache.get(p, dt) is None:<EOL><INDENT>return False<EOL><DEDENT><DEDENT>return True<EOL>
Return True if we have cached data for all projects for the specified
datetime. Return False otherwise.

:param dt: datetime to find cache for
:type dt: datetime.datetime
:return: True if we have cache for all projects for this date, False
  otherwise
:rtype: bool