California Code, Code of Civil Procedure - CCP § 2024.050

(a) On motion of any party, the court may grant leave to complete discovery proceedings, or to have a motion concerning discovery heard, closer to the initial trial date, or to reopen discovery after a new trial date has been set. This motion shall be accompanied by a meet and confer declaration under Section 2016.040.

(b) In exercising its discretion to grant or deny this motion, the court shall take into consideration any matter relevant to the leave requested, including, but not limited to, the following:

(c) The court shall impose a monetary sanction under Chapter 7 (commencing with Section 2023.010) against any party, person, or attorney who unsuccessfully makes or opposes a motion to extend or to reopen discovery, unless it finds that the one subject to the sanction acted with substantial justification or that other circumstances make the imposition of the sanction unjust.