Jain tithi calendar: what Aatham, Chaudas and Pacham mean

If you grew up in a Jain household, you probably learned the words long before you learned the calendar: aaje pacham chhe, kal aatham chhe, chaudas ni tapasya. These tithis quietly organise the month for many families. This guide explains what a tithi is, what Pacham, Aatham and Chaudas mean, and a few ways to remember them without carrying a printed panchang everywhere.

A note before we begin: observances differ between Shwetambar and Digambar traditions, between sampradayas, and even between local sanghs. This article explains the calendar in general terms. For what to observe and how, please follow your guru and sangh.

What is a tithi?

A tithi is a lunar day. The lunar month is divided into two halves, called pakshas:

• Shukla paksha (Gujarati: Sud), the bright half, when the moon grows from new moon to full moon
• Krishna paksha (Gujarati: Vad), the dark half, when the moon wanes from full moon to new moon

Each paksha has 15 tithis, which gives about 30 per lunar month. The 15th tithi of the bright half is Punam (full moon), and the end of the dark half is Amas (new moon). Because a tithi is measured by the moon rather than by a clock, it does not always begin at midnight and can start or end at any hour. That is why the same tithi can appear to “run across” two civil days, and why calendars sometimes disagree.

The first tithis, in the Gujarati names, run: Ekam (1), Beej (2), Trij (3), Choth (4), Pacham (5), Chhath (6), Satam (7), Aatham (8), Nom (9), Dasham (10), Gyaras (11), Baras (12), Teras (13), Chaudas (14), and then Punam or Amas.

Pacham, Aatham and Chaudas in one line each

Name	Number	Sanskrit name	Comes
Pacham	5th	Panchami	Twice a month (Sud and Vad)
Aatham	8th	Ashtami	Twice a month
Chaudas	14th	Chaturdashi	Twice a month

Since every tithi falls in both pakshas, each of these appears twice in a lunar month: once in the bright half and once in the dark half. A single name (“Aatham”) is therefore always completed by the paksha (“Sud Aatham” or “Vad Aatham”).

Why these tithis matter to many families

Across the Jain community, certain tithis are regarded as days for greater restraint and religious practice, called parva tithis. Beej, Pacham, Aatham, Gyaras and Chaudas are commonly counted among them, and many families also include Punam and Amas. What people do on these days varies widely. Depending on family and tradition it can include:

• Reciting or reading scripture, or visiting the temple or upashray
• Observing a fast, ekasana or ayambil
• Choosing simpler food, for example avoiding green vegetables on certain tithis (known as lilotari in some families)
• Extra time for samayik, pratikraman or silence

Pacham (Panchami). Besides being a regular parva tithi for many, Kartik Sud Pacham is widely known as Gnan Pacham (Jnana Panchami), a day dedicated to knowledge and respect for scriptures and books.

Aatham (Ashtami). The eighth tithi falls just past the middle of a half-month, and it is one of the days many families keep for a fast or simple food.

Chaudas (Chaturdashi). The 14th tithi, just before Punam or Amas, is observed by many with greater discipline. In some traditions the fortnightly pakkhi pratikraman is performed on Chaudas.

Easy ways to remember them

You do not need to memorise a calendar. A few tricks help:

Count with your hand. Pacham is five fingers, the whole hand. Aatham is a full hand plus three more. If you can count the day of the paksha, you have the tithi.

Anchor to the moon. Look at the moon. A thin crescent is around Beej. A half moon (right half lit) is close to Aatham in the bright half. A full moon is Punam. Chaudas is when the moon is almost full or almost gone.

Work backwards from Punam and Amas. Chaudas is always the day before the full or new moon. If you know when Punam is, you know Chaudas.

Think in pairs. Pacham to Aatham is three days; Aatham to Chaudas is six days. Write “5, 8, 14” on the fridge calendar.

Use a monthly rhythm. Many families anchor: “Pacham: Gnan, Aatham: fast, Chaudas: pratikraman”. Choose your own, with guidance from your sangh.

Why calendars sometimes disagree

When a tithi begins late at night or ends in the early morning, two different calendars might assign it to two different dates. Differences also arise from the method of calculation, the location used, and the sampradaya followed. This is not an error; it is a reason to ask your sangh which date they follow, particularly for fasts and festivals.

Keeping track without hunting for the panchang

This is why I made Jain Tithi: a daily Jain Panchang calendar in English, Gujarati and Hindi with the tithi, sunrise and sunset timings and a morning notification, so the day’s tithi reaches you without searching. It is made for Shwetambar and Digambar families alike, and it does not replace the guidance of your guru or sangh.

If it is useful, pass it on: use the smart link or the WhatsApp button on the app page to share with your family group or sangh. And if the app shows a tithi that differs from your sangh’s calendar, please tell me with the date and your location.

For the biggest event on the Jain calendar, read our simple guide to Paryushan Parva.