Flower Atlas CALENDAR

Diagram Guide: The Flower Atlas Calendar

The Flower Atlas Calendar drawing overlays Gregorian (civil), lunar, and traditional East Asian phenological timekeeping systems—specifically the 24 solar terms (nijūshi sekki) and 72 microseasons (shichijūni kō). These calendars divide the year into minutely observed seasonal changes based on direct observation of natural phenomena. Rooted in centuries of empirical environmental tracking and cultural codification, they reflect a timekeeping tradition in which environmental indicators—blooming flowers, insect awakenings, the onset of wind or dew—were carefully recorded and organized into a sequence of microseasons, enabling highly attuned ecological awareness across both agricultural practice and cultural life.

This circular drawing presents time as a concentric, cyclical, and multisensory visual cosmology, with the sun at its center, solstices and equinoxes as cardinal points, and layered rings marking the interaction of astronomical, civil, and ecological rhythms. It offers a framework for rethinking time as seasonal, ecological, and interdependent—and provides a scientific visualization of how civil, lunar, and microseasonal calendars interrelate through astronomical structure.

The calendar reveals the systemic relationship among its overlaid temporal systems. The 24 solar terms divide the solar year into equal 15° segments based on the sun’s longitude along the ecliptic. Each term is then subdivided into three five-day microseasons, forming a total of 72 kō, which capture fine-grained ecological changes. Gregorian months provide civil orientation, while lunar influence is embedded in the timing of seasonal shifts and traditional festivals. Together, these systems offer an integrated view of time as both astronomical and environmental.

A lunar calendar inset in the lower left corner of the composition depicts the phases of the moon across its monthly cycle. This visual emphasizes the interplay between solar and lunar rhythms, referencing older lunisolar calendars that combined both celestial bodies as timekeeping guides.

Although the 24 solar terms and 72 microseasons are fundamentally solar systems—defined by the sun’s position along the ecliptic—they often appear in lunisolar calendars due to their seasonal alignment. The first solar term, Risshun (立春), typically begins around February 4th, near the Lunar New Year. This overlap allowed traditional East Asian calendars to integrate solar and lunar rhythms, with almanacs presenting both side by side. The lunar inset in the lower corner of the diagram highlights this historical relationship, showing the moon’s phases across each month as part of a complementary cycle of time.

Structure of the Calendar

This guide outlines the structure and meaning of each concentric ring in the diagram, moving from the center ring outward:

Center Ring: The Sun

• Symbolizes the heliocentric anchor of all seasonal cycles.
• The source of solar time, ecological rhythms, and the orientation of the Earth’s orbit.

Ring 1: Degrees of the Solar Ecliptic (0°–360°)

• Represents the full 360° of Earth’s orbital path around the sun.
• Divides the year into 24 equal 15° segments—one for each solar term.

Ring 2: 24 Solar Terms (24 Sekki) by Number

• Numbers 1–24 mark the sequence of the 24 seasons (solar terms), known as 24 sekki (二十四節気).
• Each term represents a seasonal phase aligned with the sun’s position along the ecliptic (solar longitude).

Ring 3: Earth’s Revolution (Counterclockwise)

• A directional arrow shows Earth's orbit around the sun as counterclockwise, viewed from above the ecliptic.
• Reinforces the spatial and astronomical basis of the calendar’s structure.

Ring 4: Gregorian Months (Civil Time)

• The twelve months of the Gregorian calendar (January–December) are arranged clockwise.
• Anchors the calendar in globally standardized civil time.

Ring 5: Four Meteorological Seasons

• Spring, Summer, Autumn, and Winter divide the year into four color-coded quadrants.
• Reflects broad seasonal climates familiar across temperate cultures.

Ring 6: 72 Microseasons (Kō) by Number

• Each of the 24 solar terms is divided into three parts, creating 72 five-day units.
• These microseasons track subtle, observed ecological changes (e.g., leaf buds forming, insects stirring, mist thickening).

Ring 7: Start Dates of the 72 Microseasons

• Each microseason is labeled with its Gregorian start date, allowing precise alignment with modern timekeeping.
• Enables day-to-day correspondence between ecological time and civil time.

Ring 8: 365 Gregorian Days

• The outermost ring lists all 365 days of the year.
• Provides full daily resolution and synchronizes the entire system with the annual civil calendar.

Glossary of Key Terms