docs: def get_timestamp(d):
      """
      Returns a UTC timestamp for a C{datetime.datetime} object.
  
      @type d: C{datetime.datetime}
      @return: UTC timestamp.
      @rtype: C{float}
      @see: Inspiration taken from the U{Intertwingly blog
          <http://intertwingly.net/blog/2007/09/02/Dealing-With-Dates>}.
      """
      if isinstance(d, datetime.date) and not isinstance(d, datetime.datetime):
          d = datetime.datetime.combine(d, datetime.time(0, 0, 0, 0))
  
      msec = str(d.microsecond).rjust(6).replace(' ', '0')
  
      return float('%s.%s' % (calendar.timegm(d.utctimetuple()), msec))