The Europen Union's Working Time Directive.

The limit is 48 hours, and it's calculated with some averaging over multiple days, but I hope that's close enough.

https://en.wikipedia.org/wiki/Working_Time_Directive_2003

Funny thing: the Chinese constitution actually guarantees everybody a 44 hour workweek. It's generally not enforced however.

There's no LAW about it.

You get license to use the software if you abide by the terms of the license agreement. A company that asks its employees to work 60 hour weeks breaks the license agreement, and therefore cannot use the software.

The only LAW that could be written about this would be "Contracts cannot include limits on the number of hours employers ask people to work".

So maybe, yes, the megacorps get that law passed. Until then this license is binding...

Now whether the any particular legal system cares to enforce the license terms is another matter

That's not what legally-binding means.

By using the software, you agree to the terms of the license, and can in principle suffer a civil (non-criminal) lawsuit against you for breaching them.