Play with the mode button, you'll eventually find the service info, alternatively have a quick look at the manual! :I
To be honest its 12,000miles, but it give you a daily run down, counting down the days based on your milage. Also i believe you get 1000miles grace between the computer telling you it needs a service and getting it serviced, but if you miss that grace period then i'd assume your warranty will be invalidated. :I
2003 3 Door Stilo 1.2 Active, Sassy Grey, 5 disc CD Changer, plastic wheel trims - and 41.7mpg average so far. Love it, Oh yes!