You can enforce time limits for your quiz, meaning that people attempting the quiz will need to complete the quiz under a certain time limit.
Adding time limit for the entire quiz:
In this mode, attempters will need to complete the quiz under the time limit you've set. They can submit the quiz any time before the timer runs out, or their attempt will automatically be submitted at the end.
Go to the Configure tab and click on Quiz settings.
Enable the Add timer for entire quiz switch, and enter your time limit in minutes.
Click on Save changes.
Adding time limit per question:
In this mode, each question will have a timer, and attempters will need to complete each question under the time limit.
Go to the Configure tab and click on Quiz settings.
Enable the Add timer for each question switch, and enter your time limit in minutes or seconds.
Click on Save changes.