Under California Family Code section 2122, you can move to set aside a judgment for:
A motion on the grounds of fraud must be brought within one year of when the ignorant party discovered or should have discovered the fraud.
A motion to set aside because a party lied on an income or expense statement or other declaration must be made within one year after discovering the perjury, or within one year after the party should have discovered the perjury.
A motion to set aside for duress must be brought within two years of the date of entry of the judgment.
A motion based on mental incapacity must be brought within two years.
Failure to comply with disclosure requirements: This motion must be brought within one year of the date when the party discovered or should have discovered the failure to comply.
For stipulated or uncontested judgments, a motion to set aside can be brought within one year of entry of the judgment for a mistake of fact or law.
The court generally won’t set aside a judgment unless one of the criteria above is met. The court won’t set aside a judgment simply because it’s inequitable now or at the time it was made.