Depends on the uni and their own rules as to when grades are counted. My degree was at Stirling and some grades in 2nd year counted, which went well against me as I had a big upswing in late 3rd/4th year.
I know now that whenever I set a deadline, students will not look at it or think about it until about 20 days beforehand, and start work properly until (at most) 5 days before. Then I get panicked emails and calls, and then I get people handing in late with various dog-ate-my-homework excuses. None matter - my deadlines are hard and any lateness is penalised.