FAQ - Does daily overtime count towards the 40 hour a week overtime? That is, if I work 5 days of 10 hours each, I know I get overtime after 8 hours on each day. However, on the 5th day, because I have already worked 40 hours in the week, do I get overtime for the whole day, or are only the 8 hours a day of straight time that I worked counted?

Daily overtime is not used to compute the 40 hours of overtime. The explanation of California Labor Code Section 510 is in this video on California's daily overtime and working past 40 hours in the week.

When an employee works ten hours in one day, the two daily overtime hours cannot also be counted as hours worked for the purpose of weekly overtime." As such, you would should be paid 8 hours Straight Time and 2 hours Overtime for each of the 5 days. Your employer could pay you the extra overtime if they wanted to -- there is never anything illegal about overpaying. However, they are not required to double count the hours.

The best way to view it is that overtime is due after 8 hours in a day and 40 straight time hours in the week, as explained in the video.