By the way, the site was setup to use english as the default language

<globalization
            culture="auto:en-GB"
            uiCulture="auto:en"
            requestEncoding="utf-8"
            responseEncoding="utf-8"
            fileEncoding="iso-8859-15" />

Tom

Hi Joe, my browser's default language is set to en-GB, so when I clicked on the next month button, the url became
http://localhost/mojoportal/Default.aspx?visdate5=01%2f04%2f2007&pageid=4

From the above string, the date format became dd/mm/yyyy but the control still interrupted it to be mm/dd/yyyy, that's why it was showing January 2007 instead of April 2007.

I tried modified the globalisation setting in the web.config but I am still getting the same result. May be we have to modify the javascript to send all date format in yyyy/mm/dd instead of the browser's culture setting.

Any thoughts?
Tom