@almaiura/legal-deadline-calculator

TypeScript calculator for Italian civil procedural deadlines.

Handles:

• day and week terms, with the dies a quo excluded;
• free day terms, with both the dies a quo and the dies ad quem excluded;
• month and year terms ex nominatione dierum;
• historical summer judicial suspension: until 2014 01/08–15/09, from 2015 01/08–31/08;
• extraordinary Covid-19 civil suspension 09/03/2020–11/05/2020;
• Italian national holidays and Easter Monday;
• optional local holidays;
• forward roll pursuant to art. 155 Italian Code of Civil Procedure;
• prudential backward calculation, moving back to the previous business day when the date falls on a Saturday, Sunday, or holiday.

Note: this package implements general rules and must be validated against the specific use case. The summer suspension does not apply to all proceedings.

Installation

npm install @almaiura/legal-deadline-calculator

Basic usage

import { calculateDeadline } from "@almaiura/legal-deadline-calculator";

const result = calculateDeadline({
    startDate: "2026-07-20",
    amount: 30,
    unit: "days",
    direction: "forward",
    suspensions: true,
    roll: "procedural",
});

console.log(result.dueDate);
console.log(result.adjustments);

Examples

Saturday roll under art. 155 c.p.c.

calculateDeadline({
    startDate: "2016-12-04",
    amount: 20,
    unit: "days",
    direction: "forward",
}).dueDate;
// => "2016-12-27"

Holiday Friday: Saturday allowed if not itself a holiday

calculateDeadline({
    startDate: "2013-10-02",
    amount: 30,
    unit: "days",
    direction: "forward",
}).dueDate;
// => "2013-11-02"

Prudential backward deadline

calculateDeadline({
    startDate: "2013-11-13",
    amount: 10,
    unit: "days",
    direction: "backward",
}).dueDate;
// => "2013-10-31"

Summer suspension before 2015

calculateDeadline({
    startDate: "2013-07-12",
    amount: 20,
    unit: "days",
    suspensions: true,
    includeCovid2020: false,
}).dueDate;
// => "2013-09-16"

Local holiday

calculateDeadline({
    startDate: "2026-06-28",
    amount: 1,
    unit: "days",
    extraHolidays: [{ date: "2026-06-29", name: "Saints Peter and Paul - Rome" }],
}).dueDate;

API

type DeadlineUnit = "days" | "weeks" | "months" | "years";
type DeadlineDirection = "forward" | "backward";
type DeadlineRoll = "procedural" | "generic" | "none";

interface CalculateDeadlineInput {
    startDate: string; // YYYY-MM-DD
    amount: number;
    unit?: DeadlineUnit;
    direction?: DeadlineDirection;
    freeTerm?: boolean;
    suspensions?: boolean;
    includeCovid2020?: boolean;
    extraSuspensionIntervals?: { start: string; end: string; reason?: string }[];
    extraHolidays?: { date: string; name: string }[];
    roll?: DeadlineRoll;
}

roll: "procedural" replicates the prudential behaviour best suited for civil procedural deadlines:

• forward: Sundays and national/local holidays roll to the next non-holiday day;
• forward: if the calculated date falls exactly on a Saturday, it rolls to the next non-holiday day;
• forward: if the calculated date falls on a holiday Friday, the following Saturday may be valid if it is not itself a holiday;
• backward: Saturdays, Sundays, and holidays move back to the previous business day.

Build and test

npm install
npm test

npm publishing

npm version patch
npm publish --access public

For a private scoped package, use your organisation's npm configuration.