Well this is a misdemeanor offense. Many times the officer is incorrect and the knife does not qualify under PC 653K. I would advise hiring an attorney. There are no set sentences for this offense. A lot will depend upon your criminal background, the facts of the case, and your attorney.
Since it's a misdemeanor, it's punishable by a maximum of 1 year in jail. Practically speaking, if you don't have much of a criminal record, you'll probably get a few years of informal probation, a few days jail or community service, and a fine.
The second answer is incorrect. The maximum for a violation of California Penal Code section 653k is six months in county jail and/or a $1,000 fine.
That's just the maximum, but having a weapons charge on your record is something you should try to avoid if at all possible. If you can afford to hire an attorney before court, do so. If you cannot afford an attorney, appear when you are supposed to and request the services of the public defender. You may have defenses, search issues, etc. The only way to know is to discuss with an attorney.