Alright, I found the answer. I was expecting the simulator to retrieve the locale of my Mac which is United Kingdom. However the simulator is completely isolated in its own sandbox.
Hence you need to change the settings on the simulated
iPhone to United Kingdom. Then you have to kill the application process in the simulated iPhone itself and restart the application. Surprisingly the simulator keeps the new iPhone settings after a restart.
Now it works. I hope this helps someone else with a similar problem.