'TimeDelta or Quantity holding 1 day always means 24*60*60 seconds
This holds true for all timescales but UTC, for which leap-second
days are longer or shorter by one second.'

@pytest.mark.parametrize('scale', TIME_SCALES)
def test_delta_day_is_86400_seconds(self, scale):

    t = self.t[scale]
    dt_day = TimeDelta(1.0, format='jd')
    q_day = dt_day.to('day')
    dt_day_leap = (t[(-1)] - t[0])
    assert (allclose_jd(dt_day_leap.jd, dt_day.jd) ^ (scale == 'utc'))
    t1 = (t[0] + dt_day)
    assert (allclose_jd(t1.jd, t[(-1)].jd) ^ (scale == 'utc'))
    t2 = (q_day + t[0])
    assert (allclose_jd(t2.jd, t[(-1)].jd) ^ (scale == 'utc'))
    t3 = (t[(-1)] - dt_day)
    assert (allclose_jd(t3.jd, t[0].jd) ^ (scale == 'utc'))
    t4 = (t[(-1)] - q_day)
    assert (allclose_jd(t4.jd, t[0].jd) ^ (scale == 'utc'))
