---
type: Palm Sutra Concept
title: "閏月歸月 (Leap-month assignment)"
description: "A leap month sits between a month and the next; schools differ on which month a leap-month birth is charted under."
resource: https://localpapa.com/tools/yizhang.html
category: "Damo Yi Zhang Jing · Schools"
tags: [yizhang, palm-sutra, school, convention, leap-month]
timestamp: 2026-06-21T00:00:00Z
---

# 閏月歸月 (Leap-month assignment)

- **中文 / Chinese:** 閏月歸月

A leap month sits between a month and the next; schools differ on which month a leap-month birth is charted under.

## Conventions 各派做法

- **Leap = its own month (common) (閏月算本月（通行）) — default** — A leap month is charted under its own numeric month.
- **Split at mid-month (前半本月、後半下月)** — The first 15 days of a leap month count as that month; from the 16th, the next.

The [reading tool](https://localpapa.com/tools/yizhang.html) lets you pick the convention; the first option is the common default. Different choices can shift the pillars for births at late Zi or in a leap month.

---
*[All schools & conventions](./index.md) · [The four pillars](../pillars/index.md) · [Palm Sutra knowledge base](../index.md)*