Custom Timezones in Android

Is it possible to set the timezone of an android device (either a physical device or and emulator) to a timezone that doesn't actually exist (for instance, GMT+00:03 or GMT-500:00)? I tried reading the docs , and it seems like the data type supports that in theory, but I have no idea how you'd actually do that in practice, or if there's some reason it's impossible that I'm missing.