Quest Learning Modules offer the ability to administer timed assignments, which may be useful for take home quizzes or time-restricted in-class exams. To use this setting, create a new assignment, select learning module (as this is the only type where this features is offered), and enter in the full window during which students have for this assignment. 
Below this you will be given the option to set the amount of time students will have once they progress past the instruction slide of the learning module. If you do not want your students to receive immediate feedback be sure to also check the 'test mode' box. You may set a window span (example: 10am-3pm) during which time students will have access to the assignment; however, once they start the set timer will be in effect.
Any instructions can be written in, and the timed assignment is created once you click the blue 'create' button at the bottom of the screen. Your class will be able to access the assignment during the window the assignment is open for, but once they begin they will have limited time to complete it.
Note: if you want to change the timeframe for everyone, go to the settings of the assignment. If you want to reset an individual's assignment drill down into that student and hit the blue 'reset time' key–this will impact only the indicated student.