Whatever time it is when you realize it was past the time you were supposed to be anywhere.
Well, that was fun. What time is it? Oh, it's Fuck O' Clock. Fuck!
by Harold Q Poppinjay January 15, 2011
Get the Fuck O' Clock mug.
The time of day, typically in restaurants or cafeterias, between food rushes when service is very shitty and there's very little food selection. May also be used to describe times of poor service in other areas.
Tom: Wanna go get something to eat?

Jeff: No man, it's fuck you o' clock.
by Bebhanub September 11, 2010
Get the fuck you o' clock mug.
An unknown time of day. Can be past, present or future.
Hey Jack when are we leaving?

"At approximately ...fuck knows o' clock. Tomorrow."

What time is it?
"Fuck knows o' clock. Get a watch."

When did you fall asleep?
"Um, at fuck knows o' clock. I don't know!"
by HyperLynx September 23, 2016
Get the Fuck Knows o' Clock mug.