You may have noticed that even though we have passed Winter Solstice (December 21), the Sun continues to rise a little later each morning.

This is due to the fact that the Sun moves with what seems to be a very slightly slower-than-average westward daily motion in the sky (measured with respect to our uniform clock time) during this part of the year. This tends to delay both sunrises and sunsets as measured by the clock, even after the Winter Solstice.

The solar days in December are on average 24 hours and 30 seconds, while our clocks and watches are still assuming that each day is exactly 24 hours; this causes the day to shift about 30 seconds later each day. Sunrise actually starts to get earlier as measured by our clocks around January 5.