Do I celebrate a festival on India’s date or my local date in the US or UK?

follow a pañcāṅga calculated for your own city; the tithi at your local sunrise decides the day.

Hindu festivals follow the tithi (lunar day) and, for many observances, the tithi prevailing at local sunrise or at a specific time such as midnight for Janmāṣṭamī or the evening for Dīpāvalī’s Lakṣmī pūjā. Because sunrise in New York or London comes many hours after sunrise in India, the festival can fall a day earlier or later than in India.

So the correct practice is to use a pañcāṅga calculated for your location, not the Indian calendar hanging on the wall. Most community temples publish a local calendar, and the Today and Muhūrta pages on Chiluka use your location for the same reason.

If the right day is a working weekday, do the core pūjā on the correct day, even briefly in the evening, and hold the community celebration on the weekend. Fasts, especially Ekādaśī, should follow the local date.

Source: pañcāṅga rule — tithi at local sunrise (udaya-tithi)

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