[rules-users] Date format [MMM-dd-yyyy] can NOT work in Chinese environment. How to set locale or language of drools?

Hi, Friends: I am using Drools 4.0.7. I set the date format as [MMM-dd-yyyy], My machine locale is China, and the language is Chinese. I find that if I have a rule like "when date > Jan-01-2009", drools will throw exception like "Jan-01-2009 does not follow [MMM-dd-yyyy]". But if I change "Jan" to Chinese charactor which is "一月", runtime will be OK. So I think it is a locale/language issue. Is there anyway to set locale/language of drools? That is even if my environment is Chinese, I still can use the English date format? Or is there any other way can help me out? Thanks - Zeke