Android : How to get the unique TimeZone Display name in all the android devices?

I have used the below code to get the android mobile timezone display name.

String mobileTimeZone = Calendar.getInstance().getTimeZone()
        .getDisplayName(false, TimeZone.SHORT);

But running the same code in two different devices returns two different values as follows,

In Sony xperia Z1, it returns IST.

In Samsung Galaxy S3, it returns GMT+05.30.

How to get the unique value like IST or ET in all the devices.

Please help me on to solve this issue.