Definition & Meaning of "(till|until) the cows come home"

What is the origin of the idiom "till the cows come home" and when to use it?

The origin of the idiom "till the cows come home" can be traced back to rural and agricultural settings. In farming communities, cows are typically brought back to the barn or milking area at the end of the day. The phrase likely originated from the observation that cows often take their time to return home, moving slowly or grazing along the way. As a result, the expression came to represent a prolonged or indefinite period of time. It has been used in literature and everyday language for centuries to convey the idea of a lengthy or seemingly endless duration.