'Initialize the internal jd1 and jd2 attributes given val1 and val2.
For an TimeFromEpoch subclass like TimeUnix these will be floats giving
the effective seconds since an epoch time (e.g. 1970-01-01 00:00:00).'

def set_jds(self, val1, val2):

    (day, frac) = day_frac(val1, val2, divisor=(1.0 / self.unit))
    jd1 = (self.epoch.jd1 + day)
    jd2 = (self.epoch.jd2 + frac)
    try:
        tm = getattr(Time(jd1, jd2, scale=self.epoch_scale, format=u'jd'), self.scale)
    except Exception as err:
        raise ScaleValueError(u"Cannot    convert    from    '{0}'    epoch    scale    '{1}'to    specified    scale    '{2}',    got    error:\n{3}".format(self.name, self.epoch_scale, self.scale, err))
    self.jd1 = tm._time.jd1
    self.jd2 = tm._time.jd2
