Udaya Tithi: Which Tithi Counts for Festivals and Vrats?
Most observances follow the tithi at sunrise, but Pradosh, Sankashti, Shivaratri, Ganesh Chaturthi and Janmashtami follow other moments. Here are the rules.
When a tithi changes in the middle of the day, which day does the festival fall on? The answer depends on a principle called karmakala: every ritual has a prescribed time of day, and the tithi must prevail at that time.
Udaya tithi: the default rule
Udaya means rising. The udaya tithi is the tithi running at local sunrise, and for most purposes it is the tithi of the entire day. If Navami is running at sunrise, the day is Navami even if Dashami begins an hour later.
Udaya tithi is used for:
- Ekadashi fasting (Smarta tradition)
- Purnima and Amavasya in the calendar
- Most monthly fasts and general day-naming
- Choosing auspicious days for many samskaras
Because sunrise differs by location, the udaya tithi can differ between cities. Check your city's panchang.
When a different moment matters
| Observance | Tithi | Must prevail at |
|---|---|---|
| Pradosh Vrat | Trayodashi | Pradosh Kaal (around sunset) |
| Sankashti Chaturthi | Krishna Chaturthi | Moonrise |
| Karva Chauth | Kartika Krishna Chaturthi | Moonrise |
| Ganesh / Vinayaka Chaturthi | Shukla Chaturthi | Madhyahna (midday) |
| Ram Navami | Chaitra Shukla Navami | Madhyahna |
| Krishna Janmashtami | Bhadrapada Krishna Ashtami | Nishita (midnight), ideally with Rohini nakshatra |
| Maha / Masik Shivaratri | Krishna Chaturdashi | Nishita (midnight) |
| Diwali Lakshmi Puja | Amavasya | Pradosh Kaal |
| Holika Dahan | Phalguna Purnima | Pradosh Kaal, avoiding Bhadra |
| Shraddha | Pitru tithi | Aparahna (afternoon) |
Pradosh
Lord Shiva is worshipped in the twilight after sunset. So Pradosh Vrat is kept on the day Trayodashi prevails at sunset, even if it began only that afternoon. See Pradosh dates.
Sankashti Chaturthi
The fast is broken after sighting the moon, so Chaturthi must prevail at moonrise. This is why Sankashti sometimes falls a day before the udaya-tithi Chaturthi. See Sankashti dates.
Shivaratri and Janmashtami
Both are night festivals (see SpiritualMarg's guides to Maha Shivratri and Janmashtami). Shivaratri needs Chaturdashi at Nishita, the eighth muhurta of the night around local midnight. Janmashtami celebrates Krishna's birth at midnight, so Ashtami at Nishita is decisive, and the presence of Rohini nakshatra is considered especially auspicious.
What if the tithi prevails on both days, or neither?
Each festival's texts (Nirnaya Sindhu, Dharma Sindhu and regional digests) give tie-breakers:
- Both days: often the first day (purva-viddha) is preferred for some festivals and the second (para-viddha) for others. For Ekadashi, Smartas take the first day and Vaishnavas frequently the second.
- Neither day (a kshaya tithi): the festival moves to the day on which the tithi touches the required period most, or to the day it occurs.
Summary
- Udaya tithi (tithi at sunrise) is the default for naming the day.
- Many rituals have a karmakala: sunset, moonrise, midday or midnight.
- The festival falls on the day the tithi prevails at that moment.
- Our vrat pages apply these rules automatically for your location.