Hi, all, There is no code for Chinese calendar, which is mostly used by people in or from East Asia, China, Korean, Japan and so on. I just based on the code of ccal and create KCalendarSystemChinese. And I read some docs on line: http://thunder.cwru.edu/ccal/index.html http://thunder.cwru.edu/ccal/rule.htm (in Chinese) http://www.math.nus.edu.sg/aslaksen/calendar/chinese.html http://en.wikipedia.org/wiki/Chinese_calendar My code is in: http://code.google.com/p/kcalendar/ http://kcalendar.googlecode.com/svn/trunk/ cp kde4/kcalendarsystemchinese.h kde/src/KDE/kdelibs/kdecore/date cp kde4/kcalendarsystemchinese.cpp kde/src/KDE/kdelibs/kdecore/date cp kde4/kcalendarsystem.cpp kde/src/KDE/kdelibs/kdecore/date cp kde4/CMakeList.txt kde/src/KDE/kdelibs/kdecore And then build your kdelibs. You can try two examples in example/test, example/guitest. Some known issue or problem which you can help me: 1. for virtual bool setDate( QDate &date, int year, int month, int day ), what's it for? what's the difference between it with setYMD? Is it my understanding(in my current code) right or not? 2. for epoch(), what's it? 3. in my example/test, if I call weekStartDay(), it will crash, do you have any hints? 4. Just because ccal has its own calculation function, a little slow, especially when using it with KDatePicker, then I choose to like ccal, embed a data table for 1950-2050 in it, now speed is ok. Maybe some one can optimize the code of ccal, or just for my case. Regards, Liang