v2.0.2

Changes

• Add comprehensive Features section to README
• Link test validation workflow in documentation

v2.0.1

Changes

• Add npm keywords for better discoverability (epiweek, epiweeks, flusight, mmwr, epidemiology, cdc)
• Update README with npm version badge and improved package description
• Fix repository URL format in package.json

v2.0.0

Major Release

epiweek is an epidemiological week conversion tool for TypeScript/JavaScript, originally forked from reichlab/mmwr-week.
This release modernizes the package with a new stack and additional features inspired by dralshehri/epiweeks.

Highlights

• ISO week system support: Choose between MMWR (CDC) and ISO 8601 week systems
• Modern stack:TypeScript 5.x, dual ESM/CJS, Vitest, ESLint 9
• Migration from moment.js: Replaced with date-fns for smaller bundle size
• Full test coverage: The results are fully validated against Python dralshehri/epiweeks implementation

Breaking Changes

Change	v1.x	v2.0
Package name	mmwr-week	epiweek
Class name	MMWRDate	EpiWeek
Date conversion	toMomentDate()	toJSDate()
Module format	CommonJS only	ESM + CommonJS
Node.js version	≥7	≥18

New Features

• ISO week support - new EpiWeek(2025, 48, { system: 'iso' })
• Comparison methods - equals(), isBefore(), isAfter()
• Date iteration - iterDates() generator for week dates
• Lightweight deps - date-fns + micro-memoize

Migration Guide

// v1.x (mmwr-week)
import { MMWRDate } from 'mmwr-week'
const date = new MMWRDate(2025, 48)
const moment = date.toMomentDate()

// v2.0 (epiweek) - MMWR system (same behavior)
import { EpiWeek } from 'epiweek'
const date = new EpiWeek(2025, 48)
const jsDate = date.toJSDate()

// v2.0 (epiweek) - ISO week system
const isoDate = new EpiWeek(2025, 48, { system: 'iso' })

Installation

npm install epiweek
pnpm add epiweek

Full Changelog

• Renamed package and class (mmwr-week → epiweek, MMWRDate → EpiWeek)
• Added ISO 8601 week system support
• Modernized to dual ESM/CJS with TypeScript 5.x
• Replaced moment.js with date-fns
• Replaced moize with micro-memoize
• Added comparison and iteration methods
• CI with GitHub Actions (tests + epiweeks comparison)
• Updated tooling (ESLint 9, Prettier, Vitest)