No relations on Saturday night? I didn't know about that one. Bet that's honored more in the breach.
Not necessarily. There is an amusing story from Old Russia about its application to priests:
In a seminary class led by the local archbishop, the canons surrounding the celebration of the Eucharist were being taught. When the requirement to abstain from marital relations from Vespers the night before was brought up, one young seminarian was quite upset.
"But. . .but. . .Fr. Sergei, back in my village. . .he celebrates liturgy every morning. . . you mean he never. . . "
The archbishop (himself a celibate, like all Orthodox bishops) looked over his glasses at the young man, and asked, "And for what purpose did the Good Lord make the afternoon?"