Unable to change timezone on Android device using adb shell setprop

Question

I am trying to change the timezone on my android device using setprop command, but it doesn't reflect on the device (I tried restarting too)

shell@ASUS_Z010:/ $ getprop persist.sys.timezone                               
Asia/Calcutta
shell@ASUS_Z010:/ $ setprop persist.sys.timezone "America/Chicago"             
shell@ASUS_Z010:/ $ getprop persist.sys.timezone                               
Asia/Calcutta
shell@ASUS_Z010:/ $ 

Can someone give me some idea about how to achieve this, and what might be the reason of the command failing, without giving any error ?

Answer 1

I just came to know that it can only be done on rooted phones.

https://groups.google.com/forum/#!topic/android-developers/UBXrvJnxyd4

Cross verified it on a rooted phone. Bad news for me is that I can't root my testing devices on which I need to change timezones using my script.