Horse Brasses - 5 o'clock?

Relaying a question from Sniffs_Markers:

Sniffs has acquired some horse brasses (they are used to adorn the straps of horse harnesses – often they are used as decoration on people’s walls). While she was selecting her brasses, she noticed that there were several clock designs. All had the hands at 5 o’clock.

So she’s curious – why 5 o’clock on the clocks of the horse brasses?

(As opposed to say 2:40.)

Tea time? Quittin’ time for horses?

Can’t find any clock designs while searching online, so as yet, we can’t find an explanation.

Isn’t that when they are supposed to come home? oh, wait, that’s cows…sorry. :smiley: