The quiz (20 questions test) takes 20 minutes; for the HackerRank coding challenge, you have 2 hours, but usually, developers complete it for 40 minutes.
Video interview recording takes 5 minutes more.
So the quiz, task, and interview take just a bit more than 1 hour on average.
Also, you do not have to pass the quiz and the coding challenge at the same time (although why not do it this way?), you can return to your tasks within 1 week.