It very much depends on what you want to grow/raise and how you want to manage it. If your goal is to feed your family, you can pretty easily do that with a few hours of good work in a day when its all setup.
We don't do absolutely everything by hand, but we definitely avoided many of the modern approaches. We have 13 cows, 9 chickens and 20 chicks that just hatched, and a small garden (~3500 sq ft).
There's always certain jobs that take all day or multiple days, like cutting our fields (~50 acres), planting/harvesting, and butchering a pig was a huge undertaking given that we've never done anything like it before. On average, I'd say we put it 6-8 hours a day split between two people, with the occasional days of both working 8-10 hours each.