When Responses Are Due to Interrogatories
Answers are due within 30 days of the date you mail your interrogatories, plus five more for mailing unless they are personally served - the latter being a good idea when timing is critical. However, where time is not critical judges expect parties to grant reasonable requests from the other side for extensions of time. Sometimes these extensions may be granted on condition that the answering party waive any right to object to them.
The effect of not getting an extension and to not timely answer the interrogatories is that ALL objections are deemed waived by operation of law, and there is no basis for refusing to not answer all the questions in full! Don't make this mistake.
CALIFORNIA CODE OF CIVIL PROCEDURE
Response to Interrogatories
C.C.P. Section 2030.260
(a) Within 30 days after service of interrogatories, the party to whom the interrogatories are propounded shall serve the original of the response to them on the propounding party, unless on motion of the propounding party the court has shortened the time for response, or unless on motion of the responding party the court has extended the time for response.
(b) Notwithstanding subdivision (a), in an unlawful detainer action or other proceeding under Chapter 4 (commencing with Section 1159) of Title 3 of Part 3, the party to whom the interrogatories are propounded shall have five days from the date of service to respond, unless on motion of the propounding party the court has shortened the time for response, or unless on motion of the responding party the court has extended the time for response.
(c) The party to whom the interrogatories are propounded shall also serve a copy of the response on all other parties who have appeared in the action. On motion, with or without notice, the court may relieve the party from this requirement on its determination that service on all other parties would be unduly expensive or burdensome.