---
type: Concept
bundle: jyotisha-kala
bundle_version: 0.12.0
id: ayana
title: Ayana
iast: Ayana
devanagari: अयन
description: 'The Sun’s half-year course: uttarāyaṇa northward from winter solstice, dakṣiṇāyana southward from summer solstice, the coarsest solar division of the ritual year; NOT a month pair, NOT fixed to Makara Saṅkrānti, NOT a life-phase metaphor.'
darshana:
- Jyotiṣa
text_source: Vedāṅga Jyotiṣa; Sūrya Siddhānta 14
tags:
- ayana
- solstice
- calendrics
- jyotisha
- kala
not:
- term: 'a month pair'
  why: 'An ayana is six solar months, solstice to solstice: three ṛtus, half the year. It is the largest solar gear in the calendar, not a small grouping.'
  instead: 'Render ayana as the solstitial half-year and keep the Sanskrit term.'
- term: 'fixed to Makara Sankranti'
  why: 'The textbook definition is solstitial. The popular identification of uttarāyaṇa’s start with Makara Saṅkrānti was exact when the sidereal and tropical zodiacs coincided and has since drifted by the full ayanāṃśa, about 24 degrees, roughly three weeks. Treating the two as synonyms repeats the drift as doctrine.'
- term: 'a life-phase metaphor'
  why: 'Epic and devotional literature give uttarāyaṇa a valence (Bhīṣma waiting for it is the famous case). The calendrical object under the valence is an astronomical half-year, and this file documents that object.'
related:
- /concepts/ritu.md
- /concepts/samvatsara.md
- /concepts/ayanamsha.md
- /concepts/kala-jyotisha.md
timestamp: '2026-07-09'
okf_version: '0.2'
license: CC BY-SA 4.0
---

# Ayana -- अयन

**Not:** a month pair, fixed to Makara Sankranti, a life-phase metaphor

## What It Actually Means

Ayana is the Sun’s half-year course: uttarāyaṇa, the northward run from winter solstice to summer solstice, and dakṣiṇāyana, the southward return. It is the calendar’s coarsest solar division, older in Indian usage than the rāśi zodiac: the Vedāṅga Jyotiṣa structures its five-year yuga by ayanas. Ritual valence attaches to the northward course, and election prefers it for auspicious rites. The definition is solstitial; the once-exact identification of uttarāyaṇa with Makara Saṅkrānti has drifted apart by the accumulating ayanāṃśa, which makes this term a calendrical instance of the sidereal-tropical problem treated in its own file.

## Audience Metaphor

The year’s two long breaths: six months the Sun climbs north, six it descends south, an inhale and an exhale, solstice to solstice. They are the largest gears in the calendar’s gearbox, and every smaller gear, season, month, fortnight, meshes inside them.

## Citations

1. Vedāṅga Jyotiṣa structuring the yuga by ayanas -- see [references/lagadha-vedanga-jyotisha.md](../references/lagadha-vedanga-jyotisha.md)
2. Sūrya Siddhānta 14 on ayana and the solar divisions -- see [references/surya-siddhanta.md](../references/surya-siddhanta.md)
