Using the present tense to describe the future

The present is a grammatical tense used mainly to talk about events taking place now, but in German it can also be used to talk about the future. Usually this requires a reference to time to make that clear.

Das Experiment findet heute Abend statt.
Ich fahre morgen nach München.
Was machst du nach der Arbeit?
Achtung, die Sendung fängt gleich an.

It's so common in German to use the present tense to talk about the future that you hardly ever need to use the future tense.