What is a tithi?

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*[Sound: a quiet room, a page turning, a cup set down on a table. Hold 3 seconds.]*

Namaste, and welcome to the first lesson of Read a panchang. If you have ever opened a printed panchang, or a panchang app, and felt lost in its columns, this series is for you. Four lessons, slow and simple. Today, just one word: **tithi**.

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Start with the sky. The sun and the moon both move against the background of the stars. The moon moves much faster. Every month it catches up with the sun, passes it, and pulls ahead.

On the day the moon is right beside the sun, we cannot see it at all. That is **Amavasya**, the new moon. Then, night by night, the moon moves away from the sun, and a thin bright edge grows into a half, and then into a full circle. When it is exactly opposite the sun, that is **Purnima**, the full moon.

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Now here is the key idea. The panchang divides that journey, from one new moon to the next, into **thirty equal steps** of distance. Each step is twelve degrees of the moon's lead over the sun. Thirty steps of twelve degrees make the full circle, three hundred and sixty degrees.

Each of those steps is one **tithi**. A tithi is not measured by the clock. It is measured by the sky.

*[On-screen: a circle with the sun at the centre and the moon moving round it, marked in 30 slices.]*

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The thirty tithis come in two halves of fifteen.

The first half, when the moon is growing brighter, is the **Shukla paksha**, the bright fortnight. It runs from Pratipada, the first, through Dwitiya, Tritiya and so on, up to Purnima, the full moon.

The second half, when the moon is shrinking, is the **Krishna paksha**, the dark fortnight. It runs again from Pratipada up to Chaturdashi, and ends at Amavasya.

So when someone says "Shukla Ashtami," they mean the eighth tithi of the bright half. That is all.

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Now, the part that confuses everyone. Why does a tithi not line up with our dates?

Because the moon does not move at an even speed. Sometimes it moves faster, sometimes slower. So one tithi might take around nineteen or twenty hours, and another might take around twenty-six. A tithi can begin at any moment, in the middle of the afternoon, or at two in the morning.

Our calendar date, on the other hand, always runs from midnight to midnight. And in daily life, the tradition usually names a day by the tithi that is present at **sunrise**.

Put those two together, and two things can happen.

If a tithi is long, and it is present at two sunrises in a row, it covers two dates. And if a tithi is short, it can begin after one sunrise and end before the next. Then no sunrise falls inside it, and on the calendar it seems to be skipped. Nothing is lost. The tithi still happened. It simply did not touch a sunrise.

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Let us see this in a real example, Sharad Navratri this year, 2026.

According to the DharmikVibes calendar, checked against Drik Panchang for New Delhi, Navratri begins with Pratipada on the eleventh of October. Then the tithis move along. **Saptami**, the seventh, runs across two dates, the seventeenth and the eighteenth of October. Then **Ashtami** and **Navami**, the eighth and the ninth, are both observed on the same date, the nineteenth of October. The Navami tithi itself runs on into the twentieth.

So in 2026, Saptami stretches, and Ashtami and Navami come close together. Festival dates also follow their own traditional rules about which part of the day matters, and we will come back to that in a later lesson. For now, the simple point is this: nobody made a mistake. The moon set the pace.

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Here is a small thing to try this week. Open any panchang, printed or on your phone, and find today's tithi. Look at the time it ends. Then look at tomorrow's. You will start to see the moon's rhythm under the dates.

Next lesson: the **nakshatra**, the moon's path through the stars.

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This narration uses an AI voice. The lesson is written by the DharmikStudio team.

*[Sound: the page turns once more. Fade.]*

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