---
title: "What is Lunar month? | IslamicOpenFinance™"
description: "A month that begins with the new crescent moon and lasts twenty-nine or thirty days; the unit of the Hijri calendar."
url: https://islamicopenfinance.com/glossary/lunar-month/
lang: en-GB
source: "IslamicOpenFinance"
---

[Glossary](https://islamicopenfinance.com/glossary/) / [Calendar, settlement and markets](https://islamicopenfinance.com/glossary/#calendar)

Calendar, settlement and markets

# Lunar month

A month that begins with the new crescent moon and lasts twenty-nine or thirty days; the unit of the Hijri calendar.

A lunar month in the Hijri calendar lasts twenty-nine or thirty days and begins with the new crescent moon. Whether a given month has twenty-nine or thirty days depends on sighting or on the calculation method a country uses, so its length may be confirmed only at its end. Financial calculations that count Hijri months, such as zakat years or Hijri-dated maturities, must handle this variable length.

This entry explains a term; it is not a Shariah ruling. Approving a product is for each institution's own Shariah board and regulator.

## Related terms

[**Hijri calendar** The Islamic lunar calendar of twelve months, used for religious dates, zakat and, in some markets, official and business dates.](https://islamicopenfinance.com/glossary/hijri-calendar/) [**Moon sighting** Observing the new crescent moon to determine the start of a Hijri month; it decides the dates of Ramadan and the Eid holidays.](https://islamicopenfinance.com/glossary/moon-sighting/) [**Hawl** The full lunar year for which qualifying wealth must be held above the nisab before zakat becomes due on it.](https://islamicopenfinance.com/glossary/hawl/)

**Calendar, settlement and markets**

1. [Hijri calendar](https://islamicopenfinance.com/glossary/hijri-calendar/)
2. [Hawl](https://islamicopenfinance.com/glossary/hawl/)
3. [Moon sighting](https://islamicopenfinance.com/glossary/moon-sighting/)
4. [Business day](https://islamicopenfinance.com/glossary/business-day/)
5. [Value date](https://islamicopenfinance.com/glossary/value-date/)
6. [Settlement finality](https://islamicopenfinance.com/glossary/settlement-finality/)
7. [T+n settlement](https://islamicopenfinance.com/glossary/t-plus-n/)
8. [Delivery versus payment](https://islamicopenfinance.com/glossary/delivery-versus-payment/)

[All 221 terms](https://islamicopenfinance.com/glossary/)