When creating an assignment, you can offer a grace period in which late assignments will be received but marked as late in your LaunchPad gradebook. You have the option of adding a grace period to an assignment when you select the date and time it is due.
Hover over the assignment you want to give a grace period and click More Options. Then, click Edit.
Open assignment settings
Click "Assignment" or "Assign Due Date"
In the Assignment tab (or Assign Due Date depending on the LaunchPad), below the due date settings, you'll find the checkbox for Allow late submissions until grace period expires. Check this box to set the grace period.
In the example above, the quiz is set to be due at 4:00 PM with a 15-minute grace period.
This means that if a student were to look at the quiz at 4:06 PM, the student would still be able to start the quiz, but a message would indicate that the due date had passed.
After 4:15 PM (when both the due date and the grace period have expired), the student would not be able to attempt the quiz. The student would instead see a message (similar to the message below) listing the assignment policies and any previous submissions (if the quiz has multiple attempts). The student would no longer see the button to Start the Quiz.