The Tithi is the lunar day of the Vedic calendar, a unit based on the Moon rather than the Sun. This tool estimates the Tithi for any date you choose, along with its Paksha, the waxing or waning half of the lunar month. Tithis govern the timing of festivals, fasts, and ceremonies across Indian tradition, so knowing the lunar day is genuinely useful.
What a Tithi Is
A Tithi is the time the Moon takes to move twelve degrees ahead of the Sun, so a lunar month contains thirty Tithis. Because the Moon's speed varies, a Tithi is not exactly one calendar day, sometimes a little shorter, sometimes longer. The thirty Tithis split into two Pakshas of fifteen each, the bright waxing half and the dark waning half.
The Two Pakshas
Shukla Paksha is the waxing fortnight, from new moon to full moon, traditionally favoured for beginnings and growth. Krishna Paksha is the waning fortnight, from full moon back to new moon, associated with completion and release. Knowing which Paksha a date falls in adds useful context to the individual Tithi.
How the Tool Estimates It
The calculator uses a tabular synodic-month method to estimate the Tithi and Paksha for your date. This gives a result accurate to about a day for most purposes. Because real Tithis depend on the Moon's precise motion and your location, treat the figure as a close guide rather than a panchang-grade calculation.
Why Tithis Matter
Across Hindu and other Indian traditions, the right Tithi is chosen for weddings, fasts, festivals, and rituals, since each lunar day carries its own quality. Even outside religious practice, following the Tithi connects you to the Moon's rhythm, a slower and more natural cycle than the calendar date alone.
How to Use It
Enter a date and calculate. The tool gives the estimated Tithi and its Paksha, with a note on accuracy. For ritual timing, confirm against a local panchang.
Living by the Moon
Following the Tithi connects you to a rhythm older than the modern calendar, the steady waxing and waning of the Moon. Many fasts and festivals are fixed to particular Tithis rather than calendar dates, which is why Hindu festivals seem to move around the Gregorian year, they are actually staying loyal to the Moon. Ekadashi, the eleventh Tithi of each fortnight, is observed by many with a fast, while full-moon and new-moon Tithis carry their own significance. Even outside religious practice, noticing the Tithi is a lovely way to feel the lunar month turning, a slower and more natural cycle than the date on a phone screen.
Frequently Asked Questions
What is a Tithi?
A lunar day, the time the Moon takes to move twelve degrees ahead of the Sun. A lunar month has thirty Tithis split into two fortnights.
What is a Paksha?
One of the two halves of the lunar month, Shukla Paksha (waxing, new to full moon) and Krishna Paksha (waning, full to new moon).
How accurate is the estimate?
It is accurate to about a day for most purposes. For exact ritual timing, confirm against a local panchang, since real Tithis depend on the Moon's precise motion and your location.
Why do Hindu festivals change date each year?
Because they are fixed to particular Tithis, lunar days, rather than to the solar calendar, so their Gregorian date shifts while their lunar timing stays constant.
What is Ekadashi?
The eleventh Tithi of each lunar fortnight, observed by many with a fast. It is one of the better-known examples of life being timed by the Tithi.
Can a Tithi be skipped or repeated?
Yes. Because a Tithi can be shorter or longer than a day, occasionally one is skipped or two share a date, which is why a precise panchang is used for ritual timing.
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