Oh, I found a way to pass DateTime parameter to 'getLeadChanges', thx!
Actually I am coding C# without Java example.
I get 11 fields for ActivityRecord when calling 'describeMObject', but LeadChangeRecord has only 7.
So, I still want to find a way to get lead activities like 'getLeadActivity' but not to travel all the leads manually.
Do you have any suggestions?
Thank you very much!