I'm facing the same issue, when I set the above mentioned solution in my code behind, it changes every datepicker on the page, but I need this string format on only one datepicker..
Any suggestions?
Never mind, the culture is a ref field. So if you pass the current thread culture it will change the notation of the current thread culture and apply it throughout the application.
So if you want to set the same culture as the current thread, use new CultureInfo(Thread.CurrentThread.CurrentCulture.Name)