def timetz_pack(timetup_tz, dl_pack=dl_pack, mktime=mktime):
    """
	Pack a time; offset from beginning of the day and timezone offset.

	Given a pair, ((seconds, microseconds), timezone_offset), pack it into its
	serialized form: "!dl".
	"""
    timetup, tz_offset = timetup_tz
    return dl_pack((mktime(timetup), tz_offset))
