That looks like #lang frtime? http://docs.racket-lang.org/frtime/index.html

Have you tried one of the ‘Graphical Demo Programs’?

See section 5 of manual link above

> To run the following animation/GUI demos, simply set the language level to FrTime, open the corresponding file, and Execute. See the demo source code for more information.

> “analog-clock.rkt” : An animated real-time clock. A slider adjusts the radius of the face. Click and drag to move the face around.