'Set the time in UTC.
Arguments:
value -- A datetime object or properly formatted
string equivalent.'

def set_utc(self, value):

    date = value
    if (not isinstance(value, dt.datetime)):
        date = xep_0082.parse(value)
    date = date.astimezone(tzutc())
    value = xep_0082.format_datetime(date)[:(-1)]
    self._set_sub_text('utc', value)
