The definition of “1週28時間” when it comes to part time job limits on a student visa.

I started a part time job this month, and made sure to read through the laws beforehand just to make sure I don’t make any small but big mistakes. From what i understand the 一週 does not refer to Sunday-Saturday that resets every Sunday, but to any 7 days period. So from last Wednesday to this Tuesday, last Thursday to this Wednesday etc. you can not have worked more than 28 hours in that 7 day time frame…right?. I brought this up to my boss because there was a mistake in future shift scheduling that would break this rule, but he didn’t seem to understand why I was worried. I told him to keep the combined shift hours of any 7 day period below 24 (im aware max is 28) and for a single shift to not exceed 8 hours (he wrote he wanted me to work a 12 hour shift) . He said we will talk again tomorrow, and then a friend (who’s also a coworker) showed me a picture of a message from my boss to her, stating that I seem to be worried for some reason about the hours but he doesn’t understand why. I just wanted to make sure, am I understanding these limitations correctly?