what can I do if my employer changes time clock

If your employer is changing clock time in an effort to avoid paying you for hours worked, it is likely a violation of both Federal and State law.  For example, if your employer is changing clock time to avoid paying overtime hours, that would be a violation of the Fair Labor Standards Act.  If you and your co-workers are being cheated out of time, and therefore money, you should contact an employment attorney to assist you with the recovery of your wages.  Most wage and hour laws allow for the collection of attorney's fees from the employer, so there is no cost to you.  If you would like to discuss your case in more detail, please feel free to give me a call.