6 to midnight
A boner. An erection. When your dick goes from 6 o'clock to 12 o'clock (midnight).
"When I saw those pics of you online, I went from 6 to midnight!"
6 to midnight
When a guy gets an boner and flips it up to his waistband to avoid the bulge being seen. It is commonly mistaken to mean simply a boner.
I got a chubby and went from 6 to midnight so no one would see it.