Question:How can I stop students from submitting assignments after the due date has past?
Answer:There are two options for this. One is once the due date has passed, you can hide the assessment from the students. To hide the assessment you go to the settings for the assessment click on the access tab, turn on advanced options and change the End Date view restrictions. Make sure to check the check boxes next to the start/end dates to enable them.
The second option is to change the start/stop accepting submission dates. Setting the start/stop accepting submission dates will allow the students to see the assignment once the submission date has passed, but be unable to submit. This can be found by going to the settings for the assessment, clicking on the interactions tab, and setting dates in the start/stop accepting submissions, making sure to check the check boxes next to the dates to enable them.
Either way you can always see the time stamp of when a student submitted an assignment to determine if they met the deadline or not.