Legal Question in Employment Law in California

Probably not, but you should check with your HR department. I assume you are talking about a paid vacation. Under most paid vacation policies, you only use up your paid vacation days on days when you otherwise would be working. If there is a weekend during your vacation, you don't get paid for the weekend days and so they likely won't be considered vacation days counted against your paid vacation bank. I suppose if your company PAID you for the weekend days, they might be counted against your paid vacation bank, but that's not how most vacation plans work. Again, you should speak to your company's HR department to clarify. If your HR department says that weekends are counted as vacation days but the company does NOT pay you for those days because they're weekends, then there may be a wage theft issue (i.e, the company may be stealing money from you).