On Form FL-100, enter the date that best reflects when there was a complete and final break in the marriage under California Family Code section 70. That means one spouse expressed an intent to end the marriage and then acted consistently with that intent. It is not automatically the day someone moved out, filed for divorce, or stopped sharing a bedroom.
Use the facts and records to understand what the form is asking, but do not invent a precise date merely to complete the box. If two dates could materially affect property, debt, or support—or your spouse disputes the date—the legal issue may need individual advice or a court decision.
This explanation uses Family Code section 70 and the California Courts date-of-separation guide. For every other item on the petition, see the complete FormExplainer FL-100 Guide.
Jump to: What the date means · Living apart versus legal separation · Why it matters · Facts and records · If spouses disagree
What does “date of separation” mean in California?
Family Code section 70 defines it as the date a complete and final break in the marital relationship occurred. The statute requires evidence of both:
- one spouse expressing an intent to end the marriage to the other spouse; and
- conduct by that spouse that is consistent with the intent to end the marriage.
The court must consider all relevant evidence. That is why a single familiar event may be important without being conclusive. A move, a conversation, a written message, a new financial arrangement, or a divorce filing can help show what happened, but the legal question is still whether intent and consistent conduct established a complete and final break.
Only one spouse must form and communicate the intent; both spouses do not have to agree that the marriage is over. But an unspoken private thought is not enough. The intent must be expressed to the other spouse through words or conduct.
Why does FL-100 ask for the date?
Item 3 of FL-100 asks for the marriage date, the separation date, and the elapsed years and months. The court uses those dates to identify the marital period relevant to the case. The duration line is calculated from marriage to separation, not from marriage to the day you fill out the form.
Entering a date on the petition reports your position; it does not prevent the other spouse from stating a different date, and it does not by itself decide a dispute. The form begins the case and identifies issues. A stipulation or court finding resolves a contested legal date.
Is the date you moved out always the date of separation?
No. Moving out may strongly support a date, but physical separation and the legal date of separation are not identical concepts. Spouses can live in different places without a complete and final break—for example, because of work, caregiving, or a temporary conflict. They can also remain under one roof while one spouse has clearly ended the marriage and later conduct consistently reflects that decision.
Similarly, filing FL-100 is not automatically the date. The break may have happened earlier, or the facts may show that an earlier separation was temporary and the spouses reconciled. California Courts emphasizes the combination of intent and conduct rather than a rule that one address change controls.
What if we separated and then reconciled?
A genuine reconciliation can make the earlier date less likely to describe a complete and final break. Look at what happened after the claimed date rather than treating the first breakup or first move as permanently fixed. A later second break may be the relevant event. The effect of particular facts can be disputed, so this page does not select between competing dates.
Why can the date of separation matter?
The date can affect the financial boundaries of the marriage and the length of the marriage used in a support analysis. California Courts identifies three main consequences:
- Property: earnings and property acquired before versus after separation can be treated differently under California community-property rules.
- Debt: the timing of a debt can affect whether it is characterized as community or separate.
- Spousal support: marriage length is measured from marriage to separation and can be relevant to support, although it does not alone decide whether support will be ordered.
A one-day disagreement will not matter equally in every case. A disagreement spanning months or years can be consequential when substantial earnings, purchases, debts, or the duration of the marriage fall between the proposed dates.
What facts or records can help me understand the date?
Build a short timeline around both parts of the legal definition. Separate records showing what one spouse communicated from records showing how the spouses acted afterward.
- messages, letters, or emails in which a spouse clearly said the marriage was ending;
- notes or calendar entries identifying an in-person conversation;
- housing records showing when a spouse moved and whether the move was described as temporary or permanent;
- banking, payroll, insurance, tax, or household records showing financial changes after the claimed date;
- communications with family, friends, counselors, mediators, or lawyers that help establish the timeline;
- public or social conduct showing whether the spouses continued to present themselves as a couple; and
- records of a reconciliation or later return to marital life.
No single category is required in every case, and creating a separate account does not automatically establish the date. Use records to reconstruct what actually happened, not to manufacture a story after the fact. Keep originals or reliable copies and note the source and date of each item.
What happens if spouses disagree about the date?
Each spouse can state the date they contend is correct and support it with evidence. If they do not reach an agreement, the judge can decide the issue. California Courts’ example of a date-of-separation trial issue explains that the judge applies the law to the evidence and that the person asking the court to use a date must prove it.
A disagreement about the date is different from misunderstanding the FL-100 field. FormExplainer can explain the statutory standard and where the date appears on the form. It cannot weigh credibility, decide which conduct was consistent, calculate the financial consequences of two disputed dates, or choose the legally correct date from individualized facts. If the difference could affect substantial property, debt, or support, consider advice from a California family-law attorney or help identifying the court procedure from your self-help center.
Before you enter the date on FL-100
- Identify when the intent to end the marriage was expressed to the other spouse.
- Check whether later conduct remained consistent with ending the marriage.
- Distinguish a temporary move or breakup from a complete and final break.
- Compare important dates with contemporaneous records.
- Calculate the years and months from marriage to the date you use.
- If a material dispute remains, do not treat the form box as a substitute for resolving it.
Review the rest of FL-100 before filing.
Once you understand what item 3 is asking, use the complete FormExplainer FL-100 Guide to review the residency questions, children and custody requests, support choices, property and debt sections, attachments, signature, and next steps. It will help you keep the separation date consistent with the duration entry and the property information elsewhere in the petition.
After filing, the petition still must be served correctly. Our California divorce-service explanation covers the initial packet, permitted methods, proof, and timing.
Sources checked October 7, 2026: California Family Code section 70 and current California Courts guidance on date of separation and disputed trial issues.