Pre-weekend exclamation

• Letters exchanged by employees?
• Weekend-starting cry
• "Yay for the end of the week!": Abbr
• Nine-to-fiver's exclamation of relief
• "I'm so done with this week!"
• Weekly cry of relief
• Weekend-welcoming "Whew!"
• Office workers' letters

Wikipedia Word definitions in Wikipedia
TGIF is the name of a defunct American prime time television programming block that aired on the American Broadcasting Company (ABC). The name comes from the initials of the popular phrase " Thank God It's Friday "; however, the stars of the lineup touted ...

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
also T.G.I.F. , by 1946, slang abbreviation of "Thank God (or "goodness"), it's Friday" (end of the work week).