Legal Question in Employment Law in California

Make sure the time your work is documented. If your company has a Human Resource Dept., try to resolve the matter through an HR Rep. If you cannot get anywhere, you can either file a wage claim with the California Labor Commissioner, or see an employment law attorney to review your options. If many employees are similarly affected, your case may be more attractive to an attorney who handles class action claims.

Michael's advice is good. I qualify it only by observation that there is a DLSE regulation allowing for time clock rounding (both up and down), and it may be that the regulation is not being strictly followed, or that you do not understand that it is being followed. If you are using a time tracking program or "clock", check your reported hours of arrival and departure to see if the adjustments (if any) are balancing out over time.