code: def _since_epoch(cdate):
      
  
      if len(cdate) < 29:  # somethings broken
          if len(cdate) < 5:
              return utc_now()
  
      cdate = cdate[5:] # assume short weekday, i.e. do not support obsolete RFC 1036 date format
      t = -1
      for time_format in TIME_FORMAT :
          try:
              t = time.strptime(cdate, time_format)   # e.g. 18-Apr-2014 12:30:51 GMT
          except ValueError:
              pass
          else:
              break
  
      if t == -1:
          raise (Exception,
                 'ValueError: Date "{0}" does not match any of: {1}'.format(
                     cdate,TIME_FORMAT))
  
      return calendar.timegm(t)
docs: :param cdate: date format 'Wed, 06-Jun-2012 01:34:34 GMT'
      :return: UTC time