Mysticism June 11, 2026 2 min read

Meaning and Customs of Haji (夏至) — the 10th of the 24 Solar Terms, around June 21-22

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OIYO Research Team Contributor

Haji (夏至) is the 10th of the 24 solar terms, falling around June 21-22 when the sun reaches ecliptic longitude 90°.

At a Glance

CategoryDetails
Hanja夏至
Season☀️ Summer
Solar calendar periodAround June 21-22
Solar ecliptic longitude90°
Saju monthly commandMid-qi (中氣) — the middle of the month
Key themesLongest daylight, peak

Meaning and Origin

Haji is the day when the sun stands highest and daylight is the longest of the year. It is the peak of solar energy — after this day, the length of daylight begins to shorten little by little.

Customs and Foods

Around this time, people steamed and ate newly harvested potatoes called “Haji potatoes,” and when drought struck, villages held rain rituals. It is also when the full heat of summer and the rainy season begin together.

Saju and the Solar Term

Haji is a mid-qi (中氣), marking the middle of the lunar month. In myeongnihak, the boundary of the month pillar (月柱) is based on the 12 jeol (節), while the mid-qi is read as the point when that month’s energy becomes most concentrated.

Wisdom of This Time

A peak is also a turning point — the wisdom of Haji is to prepare for the next season at the brightest moment.

Learn More


Solar terms are a seasonal calendar that divides the sun’s path into twenty-four parts. This is a traditional explanation based on the climate of the Korean Peninsula, and the actual date may vary by about a day each year.

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OIYO Research Team

Research Team

The OIYO research team structures material from psychometric scales, statistics, and academic literature. We name both the popular framing and its scholarly limits, so each guide works as a tool for reflection rather than a verdict.