Besides that, its a nice app.
EDIT: Since I got downvoted for this, let me rephrase in terms of a bug report: My local time is Dublin, Ireland (so UTC) and I entered 9:30 AM as the local time. Then I changed Greenwich to Dubai. The updating was pretty slow, so before it completed, I changed the local time to 9:31 and the output I got was NaN:aN PM. I'm able to reproduce it by following the same steps (though the actual local time entered doesn't seem to matter - just that its changed before the "updating..." text disappears).