I missed a deadline. What should I do?

In this situation, it is of the utmost importance that you be proactive (see the FAQ entry on being proactive for more).

Regardless of the severity of your situation, you should take responsibility and make first contact as soon as you know you will be unable to meet the deadline.

Do not go missing-in-action under any circumstances.  Regardless of the severity of your situation, I expect you to shoot me a quick email telling me when and whether I can expect the late work. Even if the email says “I am overwhelmed; I do not know when I will be able to hand in the work,” that’s better than nothing. Do contact me. Immediately.

We will work out a plan in the best way that we can. I had a lot of trouble with deadlines as an undergraduate myself, and I’ll likely be pretty flexible.

But if we have not worked out a plan by the end of term, and been in active contact about that plan, I will not accept late work after term ends unless I am compelled to do so by university administration. In other words, if a post-term request for retroactive extensions is the first I’ve ever heard from you, I will likely reject that request. Your best bet is to contact your College Registrar to figure out a plan.