A Canvas feature for teachers to create assignments that have a set time-period allowed for each student to complete the assignment. The teacher can create assignments and customize a "hard due-date" and a "time-allotted" parameter, such that a student may see a preview of the assignment, and choose to unlock the assignment. For example, when the student chooses to unlock the assignment, they shift their version of the assignment's due date to their current time plus the "time-allotted," and must complete the assignment by the end of their given time-frame. However, no matter the fact if or when the student unlocks the assignment, the latest due-date allowed by the assignment defaults to the "hard due-date" parameter specified by the teacher upon assignment creation.