Google has a revised interactive answer box for a search for [timer], [stopwatch] and variations of them, such as [set a timer for 10 minutes]. The new interface lets you toggle between the timer feature and the stopwatch feature.
Keep in mind that you can set both to run simultaneously if you want to. There is even an option to have it beep like an alarm clock, by clicking on the speaker icon. The window option will expand the timer/stopwatch to be full-screen.
Here are a couple of screen shots:
Hat tip to Alex Chitu.