The clock of the Audi TT is located inside the RPM dial, at the bottom. The knob that sets the clock is the silver or black stalk closest to the clock. Setting the clock in the Audi TT can be tricky without the owner’s manual, and the online quick manual doesn’t mention the clock at all. The two stalks between the speedometer and RPM dial are unlabeled, and they don’t operate intuitively.
Pull outward on the silver (or black) "Stalk" that is to the immediate right of the clock. There are two such stalks. Between the two of them, you want to pull the "Left stalk" — which will be just to the right of the clock. Pull the "Stalk" outward toward yourself. The hours will then blink, if you pulled it out far enough.
Pull the "Stalk" out repeatedly to cycle to the field you want to change; this includes hours, minutes, month, day, and year.
Change the field that is blinking by rotating the "Stalk" clockwise. Set the correct time and date.