I do appreciate subtlety, but a small gray font does not lend itself well to "attention", does it? And again, localization, please, since UTC = halfway 'round the planet for some of us.
Oh come on. Message stands out enough, no need to have a gaudy 30px red font up there. And you can easily add your time offset on your own, UTC is fine as it doesn't get messed up twice a year as most timezones do.