Gianni, The discusion about the EoT is very interesting indeed. Now I will give some remarks to your message of Sat, 4 Jan 1997.
As I read in a Dutch book the definition of the EoT was : EoT = TA - TM. TA and TM as you defined. But in 1930 the IAU ( International Astronomical Union? ) changed the definition into EoT = TM - TA. Why I don't know. So there is already an international definition and I think we have to use that one. My suggestion therefore is opposite to yours. The max change in the value of the EoT in one day is about 30 seconds in December. You mentioned 20 seconds. To use on sundials your proposal for an average value at local noon is a good one. But in tables or graphs in a book or so I suggest to use the values for 12:00 UT. Nowadays we communicate world wide and such information will be spread all over the world. More important is to mention for which time the EoT is calculated and with what accuracy. Fer J. de Vries.
