Assignments that are due at 11:59pm are marked as all-day events in the Calendar Feed and do not have specific start & end times. As a result, these events do not adjust based on timezone. This is especially problematic for remote students.
For example, here's how course events appear in the Canvas Calendar for a student in a different timezone. Note the Live Discussion taking place on Thursday, Feb. 31 at 8:59am.
Here's how the same events appear in Google Calendar. Note the Live Discussion is shown all-day on Wednesday, Feb. 30th. Wrong day, wrong time.
Currently, this behavior is not reflected in the documentation.