Vedha is a touch. A day whose key time is touched by a neighbouring tithi or star, the one before the festival's own or the one after, is called viddha, pierced, and some festivals refuse it. How much touch counts differs: for Rama Navami, Ashtami for 6 nazhigai or more; for Krishna Jayanti, Saptami for even a second; for the Ekadashi fast, any Dasami at arunodaya. For the date itself, the printed almanac of your tradition decides. A book's rule explains a date; it does not overrule the almanac.
☕ A pierced day
Vyapti asks whether the festival's tithi is present at the key time. Vedha asks the opposite: is a neighbouring tithi still there? It can be the one before, as Ashtami for Rama Navami, or the one after, as Trayodashi for Shravana Dwadashi. A day touched that way is viddha, pierced.
Ahnika Grantham measures the touch for Sri Rama Navami. If Ashtami overlaps the Navami day for 3 muhurtham (6 nazhigai) or more, that is vedha and the day is set aside. Under 6 nazhigai there is no vedha (Ahnika Grantham, Vol. 1 (Sri Ahobila Mutt), pp. 330–333).
For Krishna Jayanti the same book allows no touch at all: on the morning, no Saptami and no Krithikai star, not even for a second (Ahnika Grantham, Vol. 1 (Sri Ahobila Mutt), pp. 333–334).
Kalaprakasika's Ekadashi rule is a vedha rule too: if at arunodaya “there is any part of Dhasami”, “there should be no fasting on that day” (Kalaprakasika (tr. N. P. Subramania Iyer, 1917), ch. XLV, p. 241).
Vedha does not always rule a day out. Ahnika Grantham records a maxim used for some tithis, among them Tritiya, Shashthi and Trayodashi: if the tithi is absent the next day, take the earlier day even with vedha. It says plainly that the maxim may not be used for Rama Navami or for Ekadashi.
At a glance
- Sri Rama Navami: Ashtami on the Navami day for 6 nazhigai or more (pp. 330–333).
- Krishna Jayanti: Saptami, or the Krithikai star, on the morning for even a second (pp. 333–334).
- Ekadashi fast: any part of Dasami at arunodaya, the dawn before sunrise.
- Unfit for a Vaishnava fast, in the same book's list: Shashthi touched by Panchami, Saptami touched by Ashtami (pp. 334–335).
- Jayanthi itself: Rohini with Ashtami, Navami or Dasami “without Vedhai” (Kalaprakasika (tr. N. P. Subramania Iyer, 1917), ch. XLI, p. 237).
- What Nava does: vedha is tested in some rules, not as one general step. Sri Vaishnava Ekadashi moves to the next day when Dasami holds the arunodaya. Sri Pancharatra Deepam moves to the next day when Chaturdashi holds sunrise. Sri Rama Navami is kept on the day Navami holds sunrise, with no separate Ashtami test.
Frequently asked questions
What is a viddha day?
A day whose key time is touched by a neighbouring tithi or star, the one before the festival’s own or the one after. Viddha means pierced. Many festivals refuse such a day and move to the next.
Why does the Ekadashi fast look at the dawn, not sunrise?
The Ekadashi rules test arunodaya, the dawn before sunrise. If any of Dasami is there, the day is viddha and the fast moves to the next day. That is why the Smartha and Sri Vaishnava Ekadashi can fall on different days.
Is vedha always measured the same way?
No. The books measure it festival by festival: 6 nazhigai for one, not even a second for another, any touch at dawn for a third. A rule that flattens them into one test changes the answer.
Deep dive: vedha against vyapti
Two tests that can disagree, and the order the books take them in.
⚖️ When the two tests disagree
A day can pass the vyapti test and fail the vedha test: the festival's tithi is present at the key time, but the tithi before it touched the morning. The books then say which wins for that festival. For Rama Navami, vedha of 6 nazhigai sends the festival to the next day, and it stays there even when Navami has given way to Dasami by that day's sunrise.
The order of the steps is part of the rule. Testing them all at once, as a single condition, can choose a different day.
🔗 Read first
This page builds on vyapti, which tithi owns the day.