Some words may be useful concerning Chinese Calendars on the market.

There are some points of time in a year which can not be questioned according to their correctness: solstices and equinoxes. The official astronomical data can be found here for example:

http://aa.usno.navy.mil/data/docs/EarthSeasons.php

Now at exactly that time a Change of Chi has to occur in the Chinese Calendar. One might argue on whether that has to be adjusted to Local Time or China Time, but at least the timing should be correct within a range of one or two minutes. This is the case for several calendars on the market, and it is correct for the calendar integrated in this software. Unfortunately enough it is NOT so for quite a number of printed Chinese Calendars I’ve come across. So you might wish to check whether the calendar you’re using yourself is o.k. or not.