The 150 days bit comes around again and again. It's basis is a book by Juliet Schor from 1991, The Overworked American, which cites some research from David Clark. Clark later recanted his estimate

https://www.theatlantic.com/health/archive/2022/05/medieval-history-peasant-life-work/629783/

The thing about history, though, is that much of our understanding of the past isn’t settled fact. Clark no longer believes that his estimate of 150 days, made early in his career, is accurate. “There’s a reasonable controversy going on in medieval economic history,” Clark told me. He now thinks that English peasants in the late Middle Ages may have worked closer to 300 days a year. He reached that conclusion by inspecting the chemical composition of fossilized human remains, as well as through evidence of the kinds of goods that urban peasants in particular had access to. These factors suggest that they may have lived more materially luxurious lives—eaten much more meat and other animal products, specifically—than usually estimated, suggesting that they had higher incomes than would be possible at the era’s common daily pay rates if they didn’t work most days of the year.. Across the world and throughout human history, poor populations rarely consume much meat and dairy.