Nebula42 Just one question : should I put the real time or the UTC time with the daylight savings?
Nobody knows for sure, since ZWO never published the code where they compute Local Sidereal Time from Local Date/Time and Longitude.
ZWO is somewhere conflating Daylight Saving Time into the equations, where Daylight Saving Time has no place to be.
Local Sidereal Time should be determined only from UTC, Julian Date and Local longitude. Somehow, ZWO people haven't taken any beginner Astronomy classes or read any astronomy textbooks, and they try instead to deduce Local Sidereal Time from Local Time (which includes Daylight Saving Time). Utter rubbish.
Celestial navigational only needs the Julian Date, the UTC and how many degrees of longitude your are from UTC.
Julian Date is easy to compute from Unix Time (it tells you how much time has passed from the time the Sun crossed the celestial equator in Spring). The internet or a GPS unit gives you precise UTC (which is different from British Summer Time in that UTC has no Daylight Saving offset), and you can get local longitude from GPS or Google maps. I don't know why ZWO turned such a simple thing into a bug they have not been able to fix for over 5 years now.
Chen
