Thanks all for your answers ! The precise Equation of Time calculation is a rather serious matter, I'm aware ( Hi Jim! ). Nonetheless for didactic purpose and personal understanding I've found very useful to write down a closed formula , taking into account just in elementary way the obliquity of the ecliptic and the unequal motion of the Earth . With preliminary calculations made on the basis of your prompt informations I find errors of the order of ten seconds respect to the true Equation of Time ( source Shadows 1.0). Not so bad after all ! Just for amusement I will check the formula over the entire year in a systematic way . With pleasure I'll keep you informed, supposing that you are not bored by this academic and rather useless exercise !
Alberto (45,5N 7,8E)
