code: def date_range_builder(self, start='2013-02-11', end=None):
          
          if not end:
              end = time.strftime('%Y-%m-%d')
  
          return 'acquisitionDate:[%s+TO+%s]' % (start, end)
docs: Builds date range query.
  
          :param start:
              Date string. format: YYYY-MM-DD
          :type start:
              String
          :param end:
              date string. format: YYYY-MM-DD
          :type end:
              String
  
          :returns:
              String