In a quiz, you can change the dates, timing and the number of allowed attempts for groups or users. If you want to create a Group override, groups will need to be set up in your topic. This is likely to be an administrative step, once the quiz is running. You can also create an extension for a student using the Assignment extension tool.
In the next screen, choose an override group or user/s (you can search for a user or scroll through a list) (required field)
Decide whether the group or user will require password, what dates the quiz will open and close on for this group or user/s, the time limit and attempts allowed. You only have to enter settings that are changing, not settings that are staying the same.
Click Save (or Save and enter another override)
Create an extension using the Assignment extension tool
Although set up specifically for assignment extensions (hence you can choose the assignment from a drop-down menu), you can manually add other activities (such as a quiz) to the list of 'assignments', thus providing students and staff with a consistent extension application process for all assessable items in the site.