Typically, you should serve your responsive papers 9 court days prior to the hearing. This would include a responsive declaration and an income and expense declararation if required. You will need to also serve the other side by mail with your response and prepare a proof of service which you will also file with the court.
To count the court days use this calendar http://www.lasuperiorcourt.org/CourtDateCalculator/
Disclaimer: This answer does not constitute legal advice, and should not be relied upon as such. Each situation is fact specific and therefore any legal evaluation may vary. Please note it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the relevant facts and documents at issue. This answer does not create an attorney-client relationship.
Without knowing where your case is filed, it is difficult to answer your question. However, in California, Code of Civil Procedure section 1005(b) requires responsive papers to be served on all parties and filed with the court nine court days (Monday through Friday) before the hearing. It is safer to add 5 calendar days to the 9 court days requirement if the responsive papers are served by mail.
Licensed to practice in California only; this information should not be used as legal advice in any other state or jurisdiction.
Pursuant to Code of Civil Procedure [CCP] Section 1005(b), you are required to file and serve your reponsive declaration no later than nine (9) court days prior to the date of the hearing.
However, pursuant to CCP Section 1005(c), your responsive declaration (and any other papers opposing the OSC or Motion) must be served by personal delivery, facsimile transmission (allowable only pursuant to written agreement), express mail, or other means consistent with Sections 1010, 1011, 1012 and 1013, AND reasonably calculated to ensure delivery to the other party (or parties) not later than the close of the next business day after the time the opposing papers are filed.
Please note that this answer does not constitute legal advice, and should not be relied on, as each situation is fact specific, and it is not possible to evaluate a legal problem without a comprehensive consultation and review of all the facts and court pleadings filed in the case. This answer does not create an attorney-client relationship.