Tech jobs, especially in California, usually hire you for all your time. If your work requires overtime, you work overtime without getting paid overtime. This is called an “exempt” job.

So the times you’re off on the weekends doing no work is valuable to the company because you’re recharging your mind and possibly also thinking about problems subconsciously.

I went to check my job offer, and it doesn’t mention anything about 40 hour weeks or 8 hour days.