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You are here · the whole learning forest

See the whole learning forest

Choose any route through Open Pañcāṅga. Each region gathers related questions, but the trails cross freely. Start with whatever interests you and use the Trail Compass whenever you want another turn.

The three child explorers and Gajajī use a compass to choose among many paths on a map of the learning forest.

The Moon’s changing clock

Moon trails

Explore the two halves of the lunar cycle, the names of its steps, and the ways lunar months are formed.

See the tithis in actionMove through all thirty ticks of the Moon–Sun cycle.Why do tithis and calendar dates not always align?Watch lunar-day boundaries cross civil dates and sunrises.Pakṣa: the Moon’s two wingsMeet the bright, waxing half and the dark, waning half.How the tithis are namedCount the Moon-clock ticks from New Moon or Full Moon.Special kinds of tithiCompare kṣaya and vṛddhi sunrise patterns.What are Pūrṇimā and Amāvāsyā?Visit the full-moon and new-moon calendar landmarks.Meet the twelve lunar monthsLearn their names and how their boundaries work.Amānta and pūrṇimāntaCompare two lunar-month systems with different boundary phases.

Solar motion and the year

Sun and seasons

Follow the Sun through the year and explore the sidereal star-based zodiac.

What is jyotiṣa?Begin with the science of heavenly lights and timekeeping.Meet the twelve saṅkrāntisFollow the Sun’s twelve sidereal sign crossings.What is rāśi?Meet the twelve equal sections of the sidereal zodiac.See the saṅkrāntis in actionWatch a physical orbit become twelve measured solar crossings.Meet the six ṛtusCompare six Indian seasons with the four-season year.What is Makara Saṅkrānti?See how one solar crossing becomes a named annual festival.What is ayanāṃśa?Measure the difference between two zodiac starting points.One sky, two zodiac systemsCompare the tropical and sidereal ways of numbering the zodiac.

The times a calendar rule may check

Clocks in the sky

Learn how sunrise, moonrise, weekday names, and other parts of the day help turn continuous motion into calendar results.

What is a pañcāṅga?Meet the five aṅgas, or standard calendar components.Six controlling timesMeet sūryodaya, candrodaya, madhyāhna, aparāhṇa, pradoṣa, and niśītha.Meet the seven vārasLearn the Sanskrit names of the weekdays.When tithi and vāra meetWatch two independent cycles move and see how observance rules intersect them.Four calendar words and what they describeMeet four supporting calendar terms and their different roles.What is karaṇa?A brief guide to this secondary half-tithi classification.What is a nakṣatra?Meet the Moon’s 27 star-referenced sections.What is yoga?A brief guide to this secondary 27-part calculation.

Calendar rules and cultural meaning

Observance grove

Learn about cultural and religious observances on the calendar.

Akṣaya TṛtīyāConnect Vaiśākha’s third bright tithi with generosity, beginnings, and distinct Hindu and Jain meanings.Bandi Chhor DivasMeet a major Sikh observance of collective freedom connected with the Dīpāvalī date.Buddha Pūrṇimā / VesakConnect Vaiśākha’s full moon with a major Buddhist observance of awakening, compassion, and generosity.A raised ceremonial resting couch in a Vaiṣṇava temple with Viṣṇu’s conch and discus emblems, tulasī, lotus, four lamps, and monsoon rain.Devaśayanī EkādaśīAdd the lunar month Āṣāḍha to the recurring pattern.Dhamma Cakka Day / Āṣāḍha PūrṇimāMeet the Buddhist commemoration of the Buddha’s first teaching at Sarnath.DīpāvalīFollow five festival phases through changing tithis and controlling times.Durgāṣṭamī and the Navarātri seasonsFollow nine spring and autumn phases, distinguish them from the monthly vrata, and meet their distinct conclusions.EkādaśīSee why observance calendars may choose its date differently.A dignified still life with a wooden charkha, folded white khadi, round spectacles, white flowers, and a brass lamp.Gandhi JayantiLearn why this civic commemoration recurs on 2 October in the Gregorian calendar.Gaṇeśa CaturthīCompare two monthly Caturthīs with the annual festival.A brass lamp, flowers, sprouted grains, and a neatly coiled vrata thread in a monsoon-dusk still life.Gaurī and Jayā Pārvatī vrataKeep two Gujarati Pārvatī-centered vrata beginnings distinct.Guru PūrṇimāExplore an annual occasion for honoring teachers.Hanumān JayantīConnect Caitra Pūrṇimā at sunrise with Hanumān’s courage, devotion, and service.Hartālikā TṛtīyāMeet a Bhādrapada vrata centered on Pārvatī’s steadfast devotion.The Red Fort at first light with the Indian national flag flying from a proper flagpole.India’s Independence DayLearn why this national civic commemoration recurs on 15 August in the Gregorian calendar.Jain sacred seasonKeep the Śvetāmbara eight-day season and Digambara ten-virtue season distinct.Kṛṣṇa JanmāṣṭamīConnect Śrāvaṇa’s eighth dark tithi, niśītha, and Kṛṣṇa’s birth celebration.Mahāvīra Janma KalyāṇakaConnect Caitra’s thirteenth bright tithi with a major Jain observance of Mahāvīra’s birth.Mahāvīra Nirvāṇa Kalyāṇaka / Jain DīpāvalīConnect Āśvina Amāvāsyā with Mahāvīra’s liberation and the Jain Festival of Lights.PitṛpakṣaFollow a sixteen-phase annual period for remembering and honoring ancestors.An adorned Śiva liṅga and Nandī in a stone temple lit by brass lamps at twilight.Pradoṣa vrataConnect Trayodaśī, early evening, and a recurring Śaiva observance.Prakāś Gurpurab of Guru Nanak SahibConnect Kartik Puranmashi with a major Sikh observance of Guru Nanak Sahib.Rāma NavamīConnect Caitra's ninth bright tithi with madhyāhna and Rāma's birth commemoration.Ratha SaptamīConnect Māgha’s seventh bright tithi, sunrise, and Sūrya.ŚivarātriCompare the monthly night with Mahāśivarātri.Skanda ṢaṣṭhīMeet the bright sixth lunar day associated with Skanda or Murugan.A Śiva liṅga with bilva leaves and a brass lamp beside monsoon greenery.Śrāvaṇa SomavāraSee how Monday and two disclosed Śrāvaṇa month systems meet.Sri Lankan Full Moon Poya DaysFollow Sri Lanka’s published cycle of named Theravāda Buddhist full-moon observances.Vaisakhi / Khalsa Sājna DivasConnect the opening of Vaisakh with the inauguration of the Khalsa.Vasanta PañcamīConnect spring, Pañcamī, learning, and Sarasvatī Pūjā.Tulasī leaves, a brass lamp, and a white conch arranged in a serene blue-and-gold still life.Vāsudeva DvādaśīConnect Āṣāḍha’s bright Dvādaśī with Vāsudeva.Vrata, pūjā, and observanceLearn how a documented rule connects a calendar classification with an observance.World Sanskrit DayFollow an annual Sanskrit-learning observance to Śrāvaṇa Pūrṇimā.

The learning experiment behind the forest

About the project

Read about the educational purpose, National Education Policy inspiration, World Sanskrit Day milestone, and open-source approach.

Why was Open Pañcāṅga created?Meet the educational inspiration and public-launch story.India’s long view of the skyFollow selected milestones from mathematical astronomy to spaceflight.Make your own learning adventureFollow curiosity instead of a required course sequence.Meet your guidesMeet Prīti, Ravi, Sam, and Gaja and discover what each friend brings to the team.

Try one real place and date

Sky Explorer

When you want a real example, use a limited live sky check to see how the Sun and Moon connect with the calendar vocabulary and included observances. The result gives you an example to interpret, and you choose the learning path that answers your next question.

Sky Explorer