Assuming you have properly propounded the discovery and the discovery cut-off date and cut-off on discovery motions has not passed, California Code of Civil Procedure 2016.040 requires that a party meet and confer to make a good faith and reasonable attempt to resolve the issue.
The deadline to file a Motion to Compel is 45 days if you receive an insufficient response. (see CCP 2030.300(c)) However, if no response was received at all, then there is no time limit. (See CCP 2030.290(b)) As always, it is prudent to file your meet and confer within a reasonable time. Remember, your meet and confer should be sent before filing the Motion to Compel. While there is no deadline on when your meet and confer should be completed and sent, you should provide a reasonable amount of time for the opposing party to provide you a response.
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I would probably want to know more before answering fully, like has the Trial in your case been held yet? There IS a statute, California Code of Civil Procedure section 2024.010 et seq (that means the whole section) that may answer your question. CCP 2024.020 is pasted below:
Before you file that Request for Order to Compel a Response you should generally show that the discovery was properly served, the time to answer has passed, and that you made a reasonable and good faith effort to Meet and Confer. There are sanctions in the Code of Civil Procedure if you get it wrong, so I suggest that you hire counsel to help you with filing a Request for Order to Compel Answers to the Form Interrogatories.
As stated above -- I have NOT actually stated any legal opinion, because I need to know more before I can start to form one.
Take a look at CCP 2030.290(b); see also Sinaiko Healthcare Consulting, Inc. v. Pacific Healthcare Consultants (2007) 148 CA4th 390, 404. - Generally, a meet and confer letter is not required unless there is a local rule. There is not time limit to file a motion to compel answers but keep in mind your 15-day cut-off prior to trial. I personally would take care of the issue right away because the responses to the interrogatories could lead to other questions/discovery. Discovery is complex. You should hire or consult with a local attorney.