For the purposes of your posting, I assume you are an hourly regular employee (not an independent contractor or other classification).
You are in fact asking two separate questions. As to the first, there are serious legal problems to any employer who alters an employee's timecards, even more so if the employer is doing it to make it appear as though you are working less time than you really are.
As to the second part of the question, in general, unless you are an "exempt" employee, in California you are entitled to overtime pay if you work a certain number of hours per week. If your employer is altering your timecards to avoid this obligation (and you are not an exempt employee), the employer is not complying with the law.
Disclaimer: none of the information contained above is intended as legal advice and, accordingly, should not be relied upon as such. No attorney-client relationship is formed by this communication. Attorney is licensed in California only.
No. Your employer can't shave time. Yes, you are entitled to overtime.
California law stipulates that workers who have been denied overtime pay can collect all unpaid overtime. In addition, workers may also be entitled to penalties and reimbursement of attorney fees.
Overtime pay: For many employees the overtime rate is one and one-half times their regular hourly pay for work performed after 8 hours in a day or in excess of 40 hours per week. Generally, if an employee works over 12 hours in a day she is entitled to double time for the hours over 12.
Some employees are exempt from overtime. Common exemptions are certain administrative, executive and professional employees. However, employers often misclassify an employee as exempt from overtime pay. In a court case the employer has the burden to prove that an employee is exempt. The laws concerning classification are complex, but generally favor inclusion of an employee in the nonexempt category. Just because an employee is paid a salary does not mean the employee is not entitled to overtime.
You may file a claim with the Labor Commission. The Labor Commission has limited authority,and cannot award the employee his or her attorney fees. Nor can the Board handle federal law matters or address any issues outside of wage and hour claims. A lawsuit in state or federal court evens the playing field between the employer and the employee. The employee may be better off as Labor laws provide for the payment of penalties, attorneys fees and costs to the employee who prevails at trial. This often means that the employee may be able to keep all his compensation. Negotiation often leads to a settlement both sides can accept. An employee who files a lawsuit generally has greater bargaining power. The worst that can happen to an employer in a Labor Board case is that it pays what is owed. The employer has little incentive not to oppose the employee’s claim. In a lawsuit the employer has more motivation to reach a fair settlement because the court can award penalities, interest, legal costs and fees.