Why Does Ekadashi Come Around Every 15 Days?
Ekadashi is the eleventh tithi of each paksha, which is why it turns up twice in every lunar month. Why the gap is never exactly fifteen days, why some years carry twenty-six instead of twenty-four, what tithi kshaya does to the date, and the parana window most people get wrong.
Open any panchang and Ekadashi shows up twice in the same month — once in the waxing fortnight, once in the waning one, roughly a fortnight apart. It is not a scheduling convenience and it is not approximate bookkeeping. It falls straight out of how a tithi is counted, and once that is clear, the whole year's vrat calendar stops looking arbitrary.
What a tithi is, and why the eleventh
A tithi is not a day. It is the time the Moon takes to gain twelve degrees on the Sun. Thirty of those twelve-degree steps complete one lunar month: fifteen from the new moon to the full moon, fifteen more from the full moon back to the new moon.
- Shukla paksha — the Moon waxes, Pratipada through Purnima.
- Krishna paksha — the Moon wanes, Pratipada through Amavasya.
- The eleventh tithi of each fortnight is Ekadashi.
Two fortnights, two eleventh tithis, one lunar month. That is the entire answer to why it comes twice. The gap between them lands near fifteen days rather than on it because a tithi is not a fixed length — the Moon does not travel at a constant speed, so one tithi can run about nineteen hours and another close to twenty-six. Stack a fortnight of those together and the interval comes out at fourteen days one time and sixteen the next.
Twenty-four in a year — and twenty-six in some
Twelve lunar months, two Ekadashis each, so twenty-four in an ordinary year. Each carries its own name: Utpanna, Mokshada, Shattila, Kamada, Nirjala, Devshayani, Putrada, Indira, Prabodhini and the rest.
But a lunar year runs about 354 days against the solar year's 365. That eleven-day shortfall accumulates, and roughly every third year it has grown into an extra month. The panchang inserts it as adhika mas, also called mala mas or Purushottama mas. Such a year holds thirteen lunar months, and therefore twenty-six Ekadashis. The two extra ones have their own names — Padmini in the waxing fortnight, Parama in the waning.
The Chaturmas pair — Devshayani to Dev Uthani
The Ekadashi of Ashadha Shukla is Devshayani; the Ekadashi of Kartik Shukla is Prabodhini, better known as Dev Uthani. The four months between them are Chaturmas, and by tradition weddings, griha pravesh and other large auspicious undertakings are held back until it closes.
In 2026 Dev Uthani Ekadashi falls on 20 November. Chaturmas ends with it and the wedding muhurtas reopen. Tulsi Vivah follows on 21 November, on Dwadashi, and Kartik Purnima on 24 November. Some regions keep Tulsi Vivah strictly on Dwadashi while others allow it on any day up to Kartik Purnima — both practices are accepted.
When a tithi misses the sunrise altogether
This year's Dev Uthani Ekadashi is an unusually clean example of something the calendar has to handle often. The Ekadashi tithi begins on 20 November at 07:14 and ends on 21 November at 06:30 (IST). Delhi's sunrise on those two mornings is 06:48 and 06:49 — the first comes before the tithi has started, the second after it has finished. The tithi covers neither sunrise. This is tithi kshaya, a lapsed tithi.
When that happens, the vrat is kept on the day the tithi begins, so 20 November is the observed date. Note what this depends on: the tithi's start and end are a single astronomical moment shared by the whole country, but sunrise is not. Eastern India sees the sun earlier — early enough, in this case, that the 21 November sunrise can fall inside the tithi rather than after it, which changes the reckoning there. This is exactly why the date should be checked against your own city rather than assumed, and the daily panchang gives tithi and sunrise for your location.
Parana — closing the fast correctly
The fast is broken the next day, on Dwadashi, but not at any hour that suits. The window opens after sunrise and must close before the Dwadashi tithi does; breaking it once Dwadashi has run out is held to be against the rule rather than merely late.
- The first quarter of Dwadashi is Hari Vasara, and by tradition parana waits until it has passed. It commonly runs several hours past sunrise, so breaking the fast at first light is not the correct reading.
- When Dwadashi ends shortly after sunrise, the window can be very narrow — which is why the panchang prints a parana time separately for each Ekadashi.
- Snan, Tulsi puja and daan according to one's means precede it.
Rice, and who is excused
Nearly every tradition avoids rice on Ekadashi — in some households only the person fasting, in others nobody cooks it at all. It is worth being straightforward here: the shastras give no reasoned explanation for it. The puranas offer a katha, and the practice has carried forward on that basis. The various online accounts attaching a scientific rationale to it have no textual support either, and inventing one does the tradition no favours.
The fast itself takes several forms — nirjala, phalahar, or a single sattvik meal — and nothing obliges anyone to keep the hardest one. Tradition grants exemptions plainly:
- the unwell and anyone on regular medication
- pregnant and nursing women
- young children and the very elderly
- those travelling or doing heavy physical work
Phalahar in place of nirjala, or one simple meal in place of phalahar, is an accepted substitution rather than a failure. A vrat is a discipline, not a penalty. What that discipline actually consists of is a longer question than food alone.
What people usually get wrong
- "Ekadashi is the 11th of the month." It has nothing to do with the English date. The eleven counts tithis within a paksha, and the two systems do not line up.
- "My panchang lists it on two days, so it is wrong." When the tithi is viddha, the Smarta tradition takes one day and the Vaishnava tradition the next. Both rest on their own scriptural reasoning; neither is an error.
- "You can break the fast at night." Parana belongs to the following day, inside Dwadashi — not to Ekadashi evening.
- "There are always twenty-four." Twenty-six in an adhika mas year.
- "North and South Indian panchangs give different Ekadashi days." Purnimanta and amanta reckoning change what the month is called, not which day the tithi falls on. The calculation underneath is identical.
In short
Ekadashi is the eleventh tithi of each fortnight, which puts it twice in every lunar month and twenty-four times in an ordinary year — twenty-six when an extra month is inserted. Because tithis vary in length, the interval swings between fourteen and sixteen days rather than sitting at fifteen. And the fast asks for as much attention at its close as at its start: the parana belongs to the next day, inside Dwadashi, once Hari Vasara has passed.