No. But then the founders can't offload their surplus stress onto the employees.
It's pretty difficult to start any kind of business, let alone a tech startup, by working 9-5. Think the owner of, for example, a new restaurant is working 9-5 hours? Nope.
I didn't ask about the business owner, I asked about the employees.
It's not only possible, it's the law. Unfortunately it's rarely enforced.
I've never heard of such a law. Could you cite it?