Vaishnava Calendar

Vaishnava or Smārta Ekādaśī?

Why is Ekādaśī in this app sometimes a day later than in my other calendar? It is not an error: two traditions count Ekādaśī by different rules.

In short. The app shows only Vaishnava (Bhāgavata) Ekādaśī, which must be śuddhā — pure: Daśamī has to end before Aruṇodaya, 96 minutes before sunrise. Regular Hindi calendars show Smārta Ekādaśī, so the dates may differ by a day. Smārta Ekādaśī are not supported.

Two rules

Vaishnava (Bhāgavata)Smārta
RuleEkādaśī must be pure: Daśamī ends before Aruṇodaya, 96 minutes before sunriseEkādaśī is the day on which the eleventh tithi is in force at local sunrise
Source followedŚrī Hari-bhakti-vilāsa by Sanātana Gosvāmī, Śrī Navadvīpa PañjikāRegular Hindi pañcāṅgas
In this app✔—

The difference shows when Ekādaśī begins in the last 96 minutes before sunrise. By the Smārta rule the day counts as Ekādaśī; by the Vaishnava rule it is viddhā — mixed with Daśamī — and the fast moves to the next day. See the timeline in How the festival day is counted.

What Śrīla Bhaktisiddhānta wrote

The Śrī Navadvīpa Pañjikā explains why Aruṇodaya is checked for Ekādaśī, and for Ekādaśī only: other tithis are checked at sunrise. In the English translation, quoting Śrī Caitanya-caritāmṛta, Madhya 24.337:

Abandon Ekādaśī with Aruṇodaya bidhvā and other rites with Sūrjyodaya bidhvā and observe all other Abidhvā vratas (unpenetrated rites). The former causes sin and the later brings devotion to the Supreme Lord.

Read the whole passage, including the eight Mahādvādaśīs, in Śrī Navadvīpa Pañjikā.

Questions we often get

My other calendar shows Ekādaśī a day earlier. Which one is correct?Both follow their own rule. This app is for ISKCON and Gaudiya devotees, so it follows the rules of Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura in the Śrī Navadvīpa Pañjikā, designed according to the Vaiṣṇava smṛti Śrī Hari-bhakti-vilāsa. If you are in doubt about your own fast, ask your Guru.
Can I switch the app to Smārta Ekādaśī?No. Smārta Ekādaśī are not supported; only Vaishnava ones are. This is a Vaishnava calendar, not a regular Hindi panchanga.
Is the date different for another reason too?Possibly. Besides Smārta/Vaishnava, three settings change the date: Mayapur or current location, the horizon (Celestial or Earth-sky) and the location itself.

Further reading