[Noam Kaplan]

Can anyone answer this? If this is the wrong forum, I apologize. I have a calculation to figure out the atmospheric refraction from Fred Sawyer's article in the NASS Compendium. It is based on calculations that Meeus brings in his book. Refraction changes the apparent altitude of the sun, thereby changing both the apparent declination and apparent hour angle of the sun.   Am I making a mistake when I use the apparent declination and apparent hour angle for the temporal hour calculation? The effect of a few seconds difference for atmospheric refraction on the hour angle seems to have a much bigger effect on the temporal hours.   Thanks for any help you can offer, Noam   My calculations can be seen on the web at http://www.riets.edu/stuff/suncalc/zman.js in the function temporal(localTime)