us-equity-market-calendar

The NYSE / NASDAQ trading calendar — holidays (including Good Friday and Juneteenth), 1:00 p.m. early closes, trading-day navigation, and a DST-aware is-market-open. Algorithmic, zero dependencies — every past and future year is correct.

npm install us-equity-market-calendar

Why

Python has pandas_market_calendars; JavaScript had no maintained equivalent. Existing npm packages give you federal holidays or a stale hard-coded list, but not the equity calendar with its early closes and session hours. This computes it from the rules, so it's right for any year.

import { isTradingDay, nextTradingDay, isMarketOpen, sessionClose } from "us-equity-market-calendar";

isTradingDay("2026-10-12");   // true  — Columbus Day: stocks trade (bonds don't)
isTradingDay("2026-04-03");   // false — Good Friday: stocks closed (bonds don't)

nextTradingDay("2026-07-02"); // "2026-07-06" — skips the Jul 3 holiday + weekend
sessionClose("2026-12-24");   // "13:00" — Christmas Eve early close
isMarketOpen(new Date());     // true/false, DST-correct

API

Dates are "YYYY-MM-DD" strings or Date objects (UTC calendar dates).

• getHolidays(year) → { date, name }[] — full closures.
• getEarlyCloses(year) → { date, name, closeTimeET: "13:00" }[].
• isHoliday(date) / isEarlyClose(date) → the entry or null.
• isTradingDay(date) — weekday and not a full closure.
• nextTradingDay / previousTradingDay / addTradingDays(date, n) / countTradingDays(from, to).
• sessionClose(date) → "16:00" | "13:00" | null.
• isMarketOpen(instant?) — is the regular session (09:30–16:00 ET, 13:00 on early closes) open at a Date, with America/New_York DST handled via the built-in Intl API.

Out-of-range years and malformed dates throw RangeError.

Correctness

Full-closure and early-close output is verified against the published NYSE calendar for 2025–2028 — including Good Friday, the Juneteenth start in 2022, the Saturday-New-Year non-observance rule, and the exact early-close pattern (e.g. no July 3 early close in 2026 because it's the observed Independence Day). The rules are algorithmic (nth-weekday, Easter computus, weekend observance), so the same logic extends to any year; intraday open/close is checked across both EST and EDT.

Related

The bond-market counterpart is sifma-holidays (Columbus/Veterans Day closes, 2 p.m. early closes, T+1 settlement). Part of a markets toolkit: fx-value-date · 32nds · day-count · newyorkfed.

Author

Built by Moshe Malka — engineering leader in New York City. Studio work at Quentin.Code.

MIT © Moshe Malka