Rules are data, read from official sources
Each deadline rule is written as a short, structured description — the period, the unit, the direction, the holiday calendar, the service extensions and the order of steps — kept separate from the program code so that a lawyer can review it without reading software. Every rule records:
- the citations it relies on, with links;
- the date its current version took effect, so older dates are refused rather than computed under the wrong rule;
- a source status: official (read on the court’s, legislature’s or government’s own site or official PDF), secondary (read on a reputable mirror such as Cornell’s Legal Information Institute because the official site could not be reached), or memory (never published).
The federal, California, Texas, New York, Pennsylvania and Illinois rules on this site are verified against official sources: the courts’ own rules and the legislatures’ own statute sites. Only the Florida rules are marked secondary: their text was assembled from the Supreme Court’s amendment opinions and is being re-checked against the consolidated rules. Each rule lists the sources it was read in.
Holiday calendars
Each court system has its own calendar: federal holidays under 5 U.S.C. § 6103, California judicial holidays under Code of Civil Procedure § 135, California state holidays under Government Code § 6700, and the Texas national and state holidays of Government Code § 662.003. Where a court or agency publishes an official list for a year, we use that list exactly and record the date we checked it. For other years, dates are computed from the statute and every result that relies on them says so. A test confirms that the computed dates match each official list we hold, so the computation cannot add a holiday the court does not observe.
Closures announced by order — such as a presidential closure — are recorded separately. Where courts disagreed about whether a closure counts, the calculator does not apply it but warns you when it falls inside your period.
When the law can be read two ways
Some rules are genuinely unsettled — for example, whether certain Texas state holidays extend deadlines, or how California’s 2027 change to electronic service applies to papers served in 2026. In those cases the calculator computes every reasonable reading, shows the earliest date as the deadline, and lists the others with their reasoning. Acting by the earliest date is timely under every reading.
Testing
- More than 300 worked deadlines were computed by hand from the rule text, each with a written explanation, and confirmed with a separate implementation written independently of the calculator. The calculator must reproduce every one exactly, including alternative dates. The worked examples on this site’s pages are drawn from this set, so every example you read is also a passing test.
- Randomized checks run thousands of inputs from 1995 to 2095 for every rule and service method and confirm that a deadline never lands on a weekend or holiday, and that a later trigger date never produces an earlier deadline.
- Brute-force checks compare the court-day and weekend-adjustment logic against a simple day-by-day count over random holiday calendars.
Every change to a rule or holiday list increases the data version shown under each result, and the change is described in the changelog.
Attorney review
Before a calculator page is listed in search engines, the rules behind it must be reviewed by an attorney, and the page then says “Reviewed by an attorney.” A rule added or changed after its review is shown as not yet reviewed, and a calculator page that uses it stays out of search results, until the attorney has reviewed the change.
What we do not do
We do not decide which rule governs your situation, account for court orders that change a deadline, or know about closures that were not announced publicly. Periods in hours, months and years are computed only where a calculator offers them: hours under the federal rules and the limitations periods. We do not use advertising, and calculator inputs are not stored. Nothing on this site is legal advice or a substitute for the advice of an attorney.