legal.court-deadline Unreviewed

export function courtDeadline(triggerDate: string, days: number, rule: DeadlineRule, atCourtOffice: boolean, courtClosedDays: readonly string[]): CourtDeadline

export type DeadlineRule = "within" | "at-least-after" | "at-least-before";

/** The date, and which parts of CPR 2.8 shaped it. */
export interface CourtDeadline {
  readonly date: string;
  /** 5 days or less, so weekends and bank holidays were not counted (CPR 2.8(4)) */
  readonly shortPeriod: boolean;
  /** the period ended on a day the court office was closed and moved to the next open day (CPR 2.8(5)) */
  readonly extended: boolean;
}

import { courtDeadline } from "#fune/legal.court-deadline@^1";

import { addDays, parseIsoDate } from "./dates_add_days.ts";  ← from dates.add-days ^1.0.0 · built alongside by fune
import { bankHolidays } from "./dates_bank_holidays.ts";  ← from dates.bank-holidays ^1.0.0 · built alongside by fune
import { dayOfWeek } from "./dates_day_of_week.ts";  ← from dates.day-of-week ^1.0.0 · built alongside by fune
import { type CourtDeadline, type DeadlineRule } from "./legal_court_deadline_types.ts";

/** A deadline in days by CPR 2.8: clear days, short periods, court-office closures. */
export function courtDeadline(
  triggerDate: string,
  days: number,
  rule: DeadlineRule,
  atCourtOffice: boolean,
  courtClosedDays: readonly string[],
): CourtDeadline {
  parseIsoDate(triggerDate);
  if (!Number.isInteger(days) || days < 1) {
    throw new RangeError(`days must be an integer of at least 1, received ${days}`);
  }
  if (rule !== "within" && rule !== "at-least-after" && rule !== "at-least-before") {
    throw new RangeError(`unknown deadline rule "${rule}": expected within, at-least-after or at-least-before`);
  }
  if (atCourtOffice && rule !== "within") {
    throw new RangeError("atCourtOffice applies only to a within period (CPR 2.8(5))");
  }
  if (!atCourtOffice && courtClosedDays.length > 0) {
    throw new RangeError("courtClosedDays only apply when atCourtOffice is true");
  }
  for (const d of courtClosedDays) parseIsoDate(d);

  // England and Wales holidays by year, fetched only for the years a count touches.
  const holidays = new Map<number, Set<string>>();
  const isHoliday = (iso: string): boolean => {
    const year = Number(iso.slice(0, 4));
    let set = holidays.get(year);
    if (set === undefined) {
      set = new Set(bankHolidays("england-and-wales", year).map((h) => h.date));
      holidays.set(year, set);
    }
    return set.has(iso);
  };
  const isNonWorking = (iso: string): boolean => dayOfWeek(iso) >= 6 || isHoliday(iso);

  const shortPeriod = days <= 5;
  const step = rule === "at-least-before" ? -1 : 1;
  // Walk the clear days: the trigger day is never one, and in a short period
  // weekends and bank holidays are passed over without counting.
  let cursor = triggerDate;
  let counted = 0;
  while (counted < days) {
    cursor = addDays(cursor, step);
    if (!shortPeriod || !isNonWorking(cursor)) counted += 1;
  }
  if (rule !== "within") {
    // The act or event falls on the day beyond the last clear day.
    return { date: addDays(cursor, step), shortPeriod, extended: false };
  }
  let date = cursor;
  let extended = false;
  if (atCourtOffice) {
    while (isNonWorking(date) || courtClosedDays.includes(date)) {
      date = addDays(date, 1);
      extended = true;
    }
  }
  return { date, shortPeriod, extended };
}

Install

fune build

With that line in your source, in a TypeScript project (language typescript in fune.project), fune build resolves it and its 3 dependencies, pins them in fune.lock, downloads only the TypeScript package of each, and builds the code above into your project’s .fune/build, one readable file per capability with a header linking back here. Or pin a range in fune.project and build in one step:

fune add legal.court-deadline

The manifest, vectors and README with only the TypeScript implementation. Install it without the registry with fune add ./legal.court-deadline-1.0.1-typescript.fune, or fetch it from a terminal with fune pull legal.court-deadline@1.0.1:typescript.

The whole function, every language, is one file too: legal.court-deadline-1.0.1.fune, 22,391 bytes, sha256 4d0f68c186119372dad98ecaf67bd0da6cccbe52fa52ef1d1cff22b249c29a76. It installs into a project of any language.

// fune: before legal.court-deadline

// fune: after legal.court-deadline

// fune: replace dates.add-days in legal.court-deadline
// fune: replace dates.bank-holidays in legal.court-deadline
// fune: replace dates.day-of-week in legal.court-deadline

// fune: step legal.court-deadline after <n|label>

More from the author

- **Clear days (2.8(2), (3)).** The day the period begins is not counted, and if the period ends by reference to an event, the day of the event is not counted either. - **Short periods (2.8(4)).** In a period of 5 days or less, a Saturday, a Sunday, a bank holiday, Christmas Day or Good Friday does not count. The holidays are England and Wales's, from dates.bank-holidays (which includes Christmas Day and Good Friday); the CPR apply in England and Wales only. - **Court office closed (2.8(5)).** When a period for doing an act **at the court office** ends on a day the office is closed, the act is in time on the next day it is open. Closed means a weekend, a bank holiday, or a day in `courtClosedDays` (the office's own closures, which the caller knows).

Three shapes of rule, each one of the worked examples in CPR 2.8:

| rule | example | answer | |---|---|---| | `within` | particulars of claim within 14 days of service on 2 October | 16 October: the 14th day after | | `at-least-after` | the hearing at least 28 days after notice given on 1 October | 30 October: 28 clear days between | | `at-least-before` | notice served at least 3 days before a hearing on Friday 20 October | Monday 16 October | | `at-least-before`, short | the same, hearing on Monday 20 October | Tuesday 14 October: the weekend does not count |

Every one of those is a vector (2023 for the Friday example, 2025 for the Monday one).

**Literal reading.** For `at-least-before` and `at-least-after` the date returned is the one next to the clear days, even if it is a weekend: three clear days before a Thursday hearing are Monday to Wednesday, so the rule is satisfied by acting on the Sunday before, and that is what comes back. Whether a document served that day is deemed served then is a different rule (CPR 6.14, 6.26) and is not applied here. CPR 2.8(5) is applied only to `within` periods and only when `atCourtOffice` is true: moving a "before" deadline later would break the clear days it exists to protect, so asking for it is an error.

**Not handled.** Periods in months (CPR 2.10: calendar months; use dates.add-months), periods expressed as a date or a time of day, deemed service dates (CPR 6.14, 6.26), extensions by agreement (CPR 2.11, 3.8), and the rules of other courts and tribunals. Short periods and court-office closures need the bank holiday calendar for the years they touch; outside the years dates.bank-holidays publishes, the call fails rather than guessing.

## Source

Civil Procedure Rules, Part 2, rule 2.8 "Time", Ministry of Justice, https://www.justice.gov.uk/courts/procedure-rules/civil/rules/part02, read on 23 September 2026, including all four worked examples. Bank holidays: gov.uk, via dates.bank-holidays.

## Before you rely on this

**Not professional advice.** This capability calculates legal figures from published rules. It is a software component for developers, not legal advice. Rules change and every rate here has an effective date. Check that the dates cover your case. Verify results against the official sources listed above, and have a litigation solicitor review how you use it, before anyone relies on the output. Provided "as is" under its licence, without warranty.

**Unreviewed.** This capability's implementations agree in every language and pass its published test vectors, which were worked out from the official sources cited. But no qualified litigation solicitor has yet checked those vectors, or confirmed that the capability covers the cases it claims. Treat it as a draft. Do not use it for real people, money or decisions without your own expert review. Once a qualified reviewer signs off, this notice is replaced with their name, qualification and the date. Each new version needs fresh sign-off.

1.0.1 marks it unreviewed. The code and the tests are unchanged.

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