Larger projects are usually assigned over a weekend because of the "extra time" it gives students. This is amusing because students do not utilise this extra time, instead choosing to begin work on at the very end of the weekend.
In some cases, Sunday afternoon is better stated as Sunday evening.
See also the eleventh hour.
Teachers see past it very quickly if you are a dumbfuck and can't tell him what half the words in your essay mean, when questioned.
"I walked slowly down the street to school" becomes "I sauntered languorously down the boulevard to the establishment of education" (this is overly thesaurused)