Once a task or quiz is open, learners can submit it at any time during the course. All submissions are time-stamped, allowing facilitators to see exactly when each task was submitted.
When a task has passed its due date, learners will see it marked as overdue.
To help ease the administrative burden for facilitators, learners are still technically allowed to submit after the due date and time. It is then up to you (and/or your organisation) to decide whether to accept those late submissions.
How to change the assessment due date for an entire class
If an entire class needs an extension, you have the option to change the due date for an assessed task for all learners. A manage user can do this by editing the class activation.