#@teakit/month

@teakit/month is a TypeScript year-month calculation package for ESM and browser environments.

#Guide

Use this page as the short human entrypoint. Keep detailed API behavior in the method reference pages.

#Installation & Usage

npm install @teakit/month

yarn add @teakit/month

pnpm add @teakit/month

bun add @teakit/month

deno add npm:@teakit/month

import { Month } from "@teakit/month";

const current = Month.from("2025-01");
const nextQuarter = current.add(3);

current.year; // "2025"
current.month; // "01"
Month.from("2025-01-15").toString(); // "2025-01"
Month.from(new Date(2025, 0, 15)).toString(); // "2025-01"
Month.from("2025-01-31").add(1).toString({ precision: "day" }); // "2025-02-28"
Month.from("2025-07").toString({ precision: "year" }); // "2025"
nextQuarter.toString(); // "2025-04"
Month.range("2025-01", "2025-03").map(String); // ["2025-01", "2025-02", "2025-03"]

Always create values with Month.from(...). Use diff for month differences and add or sub for month offsets.

#Package Contract

• Import Month from @teakit/month.
• Create values with Month.from(...); do not use new Month(...) or call Month(...).
• Use canonical YYYY-MM strings with exactly four year digits and a zero-padded month.
• Accept date-like strings and native Date objects at the input boundary when callers already have them; Date objects use local calendar fields, so prefer strings when timezone-free behavior matters.
• Use toString({ precision: "year" | "month" | "day" }) only when explicit output precision is needed; default toString() remains YYYY-MM.
• Read month.year and month.month as strings; month.month is zero-padded.
• Treat Month instances as immutable.
• Use Month methods instead of JavaScript date arithmetic.
• The package is browser-safe ESM and has no Node runtime imports.

#Reference Map

#LLMs

AI agents should start with LLMs, then open only the relevant method reference file. Reference pages keep human usage first and AI-specific contracts near the end.