Celtic tree calendar
Glossary · Last updated: 2026-07-26
The Celtic tree calendar popularized by Robert Graves divides the year into thirteen periods. Each is linked with a tree (Birch, Rowan, Ash, and others).
Scholars debate how much is ancient vs twentieth-century synthesis. Our app uses the common date table for accessible cultural exploration.
Example: see it on a birth date
October 8, 2021 falls in the Ivy moon on the Celtic tree calendar.
Tree months have their own start and end dates. Libra is the Western sun sign for this birthday, which can be a different span.
Enter your own date on the Zodiac Sign Calculator.
Thirteen moons
Some versions tie trees to lunar months rather than fixed Gregorian slices. We document the fixed-date mapping used in our calculator.
Related
Main reading and tools
These are the main reading and calculator pages. Use them for a daily note, a birth-sign tool, or a pair check.
- Today's Horoscope hubAll twelve Western sun-sign daily pages, plus links to the seven-tradition reader.
- Horoscope & Zodiac CompatibilityTwo birth dates for Western, Chinese, and Indian Vedic pairing, plus every sun-sign hub.
- Zodiac Sign CalculatorWestern sun sign from birth date, with element, modality, and ruler.
- Rising Sign CalculatorIndian Vedic Lagna estimate when you have birth date, time, and place.
- Moon Sign CalculatorIndian Vedic Janma Rashi and nakshatra when birth time and city are available.