Legal Question in Criminal Law in California

It is called "conforming the charges to the proof." The judge can allow a change in the dates, or even allow additional charges raised by the testimony and other evidence, at any time before the case is submitted to the jury, as long as it does not affect the rights of the defendant.

For example, if you were in jail until Tuesday morning, and you were charged with a crime committed Monday afternoon, you would have a great alibi. Let's say the DA made a mistake and accused you of committing the crime on Wednesday.

After the whole trial is over, the judge can't change the date to Monday without giving you a chance to present your alibi. (Of course, it it came our during the trial that everybody was talking about Monday, not Wednesday, your attorney should have presented the alibi then.)

If the evidence showed that there was just a typographical mistake about the date, which was corrected by the testimony at the trial, then there is probably no problem with amending the allegation submitted to the jury.