Homework deadline grace period

[jprk]

Add a grade period to a homework deadline. The grace period shall be lecture-dependent. The final deadline will be therefore equal to <deadline>+<grace time>. However, only <deadline> will be used when displaying deadlines.

[jprk]

Nope. Grace period shall be a part of system settings. The whole setup has to be consistent and all homework deadlines shall work the same way.