The Naval Observatory sun azimuth table always calculates as North 360° minus sunset azimuth equals sunrise azimuth within a third of a degree, throughout the year.

For example our local 21 June Solstice is listed as sunset 303.6°, sunrise as 56.5, so North 360°. minus 303.6 equals 56.4.

Here in Saratoga Springs NY, the sun's [actual] azimuth at sunset 11 Apr. 06 was approx. 304°. The sun's [actual] azimuth at sunrise was approx. 104°. Using the N.O. formula, North 360°. minus 304 should equal 56°. The actual calculation of 104° is a whopping 48° off!

And the [actual] sunset azimuth today exceeds the government's own calculated azimuth more than nine weeks away! I simply used my Silva orienteering compass to get the approximate actual bearing for sunrise and set and compared them to the table calculated by the U.S. Naval Observatory website.