Consider this;
It's the first Friday afternoon of the new term. The teacher
hands out the homework to the students for the weekend. Monday comes, and as we know,
students being industrious and hard-working
hand in the homework to the teacher for marking... The following Friday the teacher
returns the marked homework from the previous Friday,
and hands out new homework for the coming weekend. The next Monday the students
return their completed homework for marking... and so on ad infinitum.
Is this familiar?