Changing the current thread culture Info not working

Hi,

iam trying to set a culture info different than the current culture info on the system, the code compiles fine, but nothing happens, and the system culture is the one used for the program.

here is the code :

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CultureInfo ci = new CultureInfo("ar-SA"); // arabic Saudi Arabia
ci.DateTimeFormat.Calendar = new HijriCalendar();

Thread.CurrentThread.CurrentCulture = ci;
Thread.CurrentThread.CurrentUICulture = ci;


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why is it not working? am i missing something?

even if the culture info on the system is "ar-SA" and tried to change the current thread current culture to "en-US", also nothing happens, why????????

thank you