In jewish tradition, Fridays used to be the opposite of the sabbath.
The sabbath were austere, silent contemplations of the divine. Fridays were the days you could throw all that po-faced stuff out the window and go party, with the lord´s blessing.
Holy wine was consumed, kosher dinners were especially made for the occasion. When everyone got thoroughly smashed, they would receive a blessing from their local rabbi.
This opposite-sabbath-celebration was excellent for giving the right mindset of suffering, rest and contemplation for the sabbath the following day.
The anti-sabbath Friday was called Yeehoo.