Close of Play
Even in America, play does not close, play ends. But this is not play: it is not fun. If it was fun, they wouldn't call it "work".

I suspect you mean "...end of the day..." or, perhaps even more fittingly, "End of business hours". I'll even, grudgingly, accept a TLA here if you are particularly lazy.
(MrOli is ugly, but in the morning you will be sober, Fri 9 Apr 2010, 11:55, 3 replies)

Cricket
I would assume it comes from this... you have Close of play at the end of each days play in a test match
(Bonzodog29 is an unemployed sponge of the worst kind, Fri 9 Apr 2010, 13:53, closed)

Yep.
You've just been hit for six, Oli! Back to the mong bus with you! Durrrrrr!
(The Boy Monders I have ginger bits in my beard., Fri 9 Apr 2010, 14:00, closed)

Crikey!
I do indeed stand corrected! :-)

Still hate the phrase though, even if work is as boring as cricket...
(MrOli is ugly, but in the morning you will be sober, Fri 9 Apr 2010, 14:07, closed)