The DUE date vs. the DO date

Wednesday night was exam night for my precious snowflakes, and I should have been prepared for the horror. When three students asked me before the exam review, "Does the final replace our lowest exam grade?" (answer: Yes, just like the syllabus says, and like I have said in class after the first two exams ), and then another one asked the same question as soon as we began the review, and then another asked the same question at the end of the review, that should have been a red flag. But I still wasn't ready for the looks of sullen despair, the frequent heavy sighs, the people handing in the test and trudging out thirty minutes early with most of the answers still blank (an aside: leaving early without even attempting to answer all the questions astounds me, and not in a good way. If you are ever in a class I teach and pull this crap, pray that you are not on the borderline between two grades, because you WILL get the lower one). I also was not ready to have to wake a student from a mid-test nap, but that's another story.
After an hour of post-test grading, I couldn't take any more, and went home for a rest. That's when I made the mistake of checking my messages, two of which were from a student who was absolutely flabbergasted that there was an online homework assignment due that night, and was not at all in the mood to work on more material half an hour after the exam.
Now, I should mention that all the homework is online, there's instant feedback if you do something wrong, and if you do miss a question, you can try a "similar exercise" until you get it right. Basically, there's no excuse for getting a low homework score, which is fine by me, because I consider homework to be practice for the exam, and this particular setup is excellent practice. I don't happen to agree with our coursewide due dates, which delays the due dates for several sections until after the exam which includes that section (I think it defeats the purpose of using homework to prepare for the exam; see previous sentence), but it's not a battle I've felt like fighting. Besides, most students are doing the assignments as soon as we cover the material, and sometimes beforehand - the assignments have been available since the beginning of the term.
That's really the thing that wound me up about these messages. I didn't reply, of course - the student was obviously just venting some post-exam frustration - but when the assignment (with due date displayed) available the entire semester, and when we've covered this particular section a full week before the exam, how is one still surprised to find it's due that night?
The final sentence of the second message asked, "from now on, can we be assigned the homework problem sets on days that we don't take a test on?" After several days of mulling this over, I have decided that the student is right, the assignments shouldn't be due right after the exam. I will thus be going against the course policy (with the permission of the coordinator, of course) and changing the due dates for two of the sections.
To the day BEFORE the exam.