date-light

The date helpers you actually ship. Nothing else.

39 fully typed date utilities in ~3.11 KB minzipped. Zero dependencies. Immutable by default.

Install · Why date-light? · Docs · API

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Why date-light?

Most apps only need a small, predictable slice of date-fns: format a date, parse input, add a few days, compare ranges, snap to day/week/month boundaries.

date-light keeps that slice tiny:

• 3.11 KB minzipped for 39 common utilities
• Zero runtime dependencies
• TypeScript-first with generated declarations
• Immutable functions that never mutate input dates
• date-fns-style API surface for the common calls people reach for most
• ESM + CJS package entrypoints verified before release

import { addDays, differenceInDays, format, startOfWeek } from "date-light";

const launch = new Date(2026, 5, 30, 14, 30);
const reminder = addDays(launch, -7);

format(launch, "yyyy-MM-dd HH:mm"); // "2026-06-30 14:30"
format(startOfWeek(launch), "yyyy-MM-dd"); // "2026-06-29"
differenceInDays(launch, reminder); // 7

Install

npm install date-light

yarn add date-light
pnpm add date-light
bun add date-light

Works in Node.js 18+ and modern browsers.

What You Get

import {
  format,
  parseISO,
  addDays,
  addMonths,
  differenceInDays,
  isBefore,
  isWeekend,
  startOfDay,
  endOfMonth,
} from "date-light";

Area	Utilities
Format & parse	format, parseISO, parse
Add & subtract	addDays, addMonths, addYears, addHours, subDays, more
Differences	differenceInDays, differenceInMonths, differenceInYears
Compare	isBefore, isAfter, isEqual, isSameDay, isSameMonth
Query	isWeekend, isLeapYear, isValid, getDaysInMonth
Start & end	startOfDay, endOfWeek, startOfMonth, endOfYear, more

Full list: API Reference

The Tradeoff

date-light is intentionally not a calendar platform. It does not include locales, timezone databases, duration objects, plugins, or chainable wrappers.

That is the point. For those jobs, use Intl, Temporal, Luxon, or date-fns directly. For common app date utilities, keep the dependency small.

Size

Library	minzipped	Note
date-light	3.11 KB	39 functions, fully tree-shakeable
dayjs	2.97 KB	Core only
date-fns (20 functions)	18.34 KB	Same common-operation comparison
date-fns (full)	261.3 KB	Full package

date-light (39 functions) is 5.9x smaller than importing 20 comparable date-fns functions and remains close to dayjs core size while covering a broader utility surface.

Documentation

• Getting Started
• API Reference
• Migration from date-fns
• Benchmarks
• Development

License

MIT 2026

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