sifma-holidays

July 11, 2026 · View on GitHub

The US bond-market calendar — holidays, 2:00 p.m. early closes, and settlement-date math per SIFMA's recommendations. Zero dependencies.

npm install sifma-holidays

Why

The bond market does not keep the stock market's calendar. Fixed income closes on Columbus Day and Veterans Day while equities trade; it observes early closes around holidays; and whether Good Friday is a full close or an early close varies year by year (2026: a 12:00 p.m. early close). Every existing npm calendar package models NYSE. If you compute Treasury settlement dates (T+1) with a stock-market calendar, you will be wrong several times a year.

import { settlementDate, isBusinessDay, getEarlyCloses } from "sifma-holidays";

settlementDate("2026-11-10");  // "2026-11-12" — skips Veterans Day (stocks trade that day)
settlementDate("2026-07-02");  // "2026-07-06" — skips the July 3 close + weekend

isBusinessDay("2026-10-12");   // false — Columbus Day (bond market closed, NYSE open)
isBusinessDay("2026-12-24");   // true  — early close is still a trading day

getEarlyCloses(2026);
// [{ date: "2026-04-03", name: "Good Friday", closeTimeET: "12:00" }, … 14:00 closes]

API

  • getHolidays(year) → { date, name }[] — recommended full closes
  • getEarlyCloses(year) → { date, name, closeTimeET }[] — "14:00" or "12:00" ET
  • isHoliday(date) / isEarlyClose(date) → the matching entry or null
  • isBusinessDay(date) → weekday and not a full close
  • nextBusinessDay(date) / previousBusinessDay(date) → "YYYY-MM-DD"
  • addBusinessDays(date, n) — n may be negative
  • settlementDate(tradeDate, days = 1) — regular-way settlement (US Treasuries are T+1)
  • PUBLISHED_YEARS — years backed by official SIFMA data

Dates are "YYYY-MM-DD" strings (recommended) or Date objects read as UTC calendar dates; impossible dates throw.

Published data vs. projections

Years in PUBLISHED_YEARS (currently 2026) use SIFMA's official recommendations verbatim. Other years are rule-derived projections: fixed rules (third-Monday holidays, Saturday→Friday / Sunday→Monday observance, Easter computus for Good Friday, business-day-before early closes) that reproduce SIFMA's published dates — the 2025 test suite confirms the projection matches SIFMA's published 2025-12-31 early close. The known wobble is Good Friday: projections treat it as a full close, but in some years (like 2026) SIFMA recommends an early close instead. The data table is updated as SIFMA publishes new years.

This package covers the US recommendations only (not SIFMA's UK/Japan calendars).

Part of a small fixed-income toolkit: 32nds (Treasury quote notation) · day-count · accrued-interest · treasurydirect (auction data client).

Author

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

MIT © Moshe Malka