Yes, the possessive form of the noun week is the correct form for 'the end of the week' (the week's end).
The duration of This Week in Baseball is 1800.0 seconds.
Week-end at Zuydcoote was created in 1949.
Bon week-end or Aie/Ayez un bon week-end !
The Week ended in 1941.
This Week in Baseball was created on 1977-04-01.
No, it's a noun. Incidentally, "end of the week" is not a sentence, it is a phrase.
The duration of Week-End at the Waldorf is 2.17 hours.
The duration of Week-End in Havana is 1.35 hours.
le week-end - la fin de semaine
Week-End at the Waldorf was created on 1945-10-04.
Week End Tour was created on 2004-10-04.