Here's a source I found for the UK at least:
https://neweconomics.org/2019/03/average-weekly-hours-fell-faster-between-1946-and-1979-than-post-1980
Here's a source I found for the UK at least:
https://neweconomics.org/2019/03/average-weekly-hours-fell-faster-between-1946-and-1979-than-post-1980