"Panchang" means five limbs. Most people use one without ever being told what the five are, which makes it feel like a list of names to memorise. It is not. Each limb is a measurement, and four of the five come from just two numbers: where the Sun is and where the Moon is.

Tithi — the Moon pulling away from the Sun

Take the Moon's longitude, subtract the Sun's, and divide the result by 12 degrees. That is the tithi. There are thirty of them in a lunar month because 360 divided by 12 is 30.

This is why a tithi is not a day. The Moon's speed varies — it is closer to Earth at some times than others — so a tithi can run anywhere from about 19 to about 26 hours. Some tithis are skipped entirely and some occur on two consecutive sunrises.

Nakshatra — where the Moon is against the stars

Divide the sidereal zodiac into 27 equal parts of 13 degrees 20 minutes each. Whichever part the Moon occupies is the nakshatra. Each is quartered into padas of 3 degrees 20 minutes.

The Moon crosses one nakshatra in a little under a day. This is the limb that anchors the Vimshottari dasha: the nakshatra the Moon occupied at your birth decides which planet's period you were born into and how much of it remained.

Yoga — the two luminaries added

Add the Sun's longitude to the Moon's, and divide by 13 degrees 20 minutes. That gives one of 27 yogas. Adding two longitudes has no obvious physical meaning, which is worth being honest about — it is a traditional construction rather than an observation of anything.

Karana — half a tithi

The same elongation as the tithi, divided by 6 degrees instead of 12. So each tithi contains two karanas, sixty in a lunar month, drawn from a repeating set of eleven.

Vara — the weekday

The only limb that has nothing to do with the Sun and Moon's positions. It is simply the day of the week, each ruled by a graha, and it runs from sunrise to sunrise rather than from midnight.

Why your panchang differs from another one

Three ordinary reasons, none of them an error:

  • Place. Sunrise in Chennai is about forty minutes different from Delhi. Since the panchang day begins at sunrise, everything shifts with it.
  • Ayanamsa. Nakshatra depends on the sidereal zodiac. A panchang using Raman rather than Lahiri will occasionally report a different nakshatra near a boundary.
  • Which moment is quoted. Some panchangs give the tithi at sunrise, others the one running for most of the day.

Our panchang calculates for the place you choose and states the ending time of each limb, so you can see for yourself where the boundaries fall.