In order to survive economically and insure the best health for your cows you must milk two or three times per day. Robotic milking operations allow cows to be milked "continuously," will some higher yield cows milking four or five times per day.
Worked on a ranch in E. Oregon one summer many years ago, just to see what it was like. They had two cows kept for fresh milk and butter, and to produce a calf for slaughter as a yearling.
This was milking by hand, and always twice a day. I made the butter manually, as well. Didn’t have any kind of churn, so I would put the cream from a couple days plus enough milk to have 1.5 quarts in a 2 quart mason jar, and shake that sucker until butter formed.
Hard work, but I was young and dumb.