閏年

• Reading: うるうどし
• Romaji: uruudoshi
• Kanji breakdown: 閏 (jun/uruu) — intercalary, leap; 年 (nen/toshi) — year
• Pronunciation: /ɯ.ɾɯː.do.ɕi/

Meaning

Leap year; a year with an intercalary day (29 February) added to synchronise the Gregorian calendar with the solar year.

A noun used in calendar and date-related contexts. The Gregorian calendar inserts a leap day every four years, with exceptions for century years not divisible by 400. The character 閏 (uruu) also appears in 閏月 (intercalary month in the lunar calendar). The reading うるうどし is the standard spoken form.

Examples

1. 2024年は閏年なので、2月が29日まである。 Since 2024 is a leap year, February has 29 days.
2. 閏年に生まれた人は誕生日が4年に一度しかない。 People born in a leap year only have a birthday once every four years.
3. 閏年の計算には400で割り切れる年かどうかも考慮する必要がある。 Calculating leap years also requires considering whether the year is divisible by 400.

Usage Guide

Context: calendar, dates, mathematics, astronomy

Tone: neutral

Origin & History

The character 閏 derives from the Chinese concept of intercalation — adding extra days or months to keep calendars aligned with astronomical cycles. The native Japanese reading うるう is thought to relate to 潤う (to be plentiful, to overflow), reflecting abundance of time.

Cultural Context

Era: Modern

Generation: All ages

Social background: Universal