In the Law, yes, the Fair Labor act was enacted during his presidency. But the Idea of 8 hours of work, 8 hours of sleep, 8 hours for what you will long predate

In the Law, yes, the Fair Labor act was enacted during his presidency. But the Idea of 8 hours of work, 8 hours of sleep, 8 hours for what you will long predates him, and 8 hours was already a standard shift at some (many?) factories by that time.