I have found the full problem:
If the meeting request is a recurrence events, say one week, then the first day, the time is correct, and for time weeks later, it will advance one day. For it only calculate the recurrence based on the start date.
For example:
I organize one meeting request in PDT, say that there is a meeting to occure evey week on 17:30-18:30 since 5,August, then on Zaurus, (GMT+8), the first occurence is correct, 6,August(8:30-9:30), later occurence will based on the begin date- 5,August +7,+14, ... , the time is also 8:30-9:30, that's the problem lies.
Is there any one know the solution? It seems that I can only rely Sharp guys to solve it.
Thanks.