Hello! The day of observing the Ekadashi fast is considered to be the 11th or 26th lunar day, which began at least 96 minutes before sunrise. If later, then it is postponed to the next day. On March 2 in St. Petersburg, sunrise (7:56) and the onset of the 26th lunar day (7:46) occur with a difference of only 10 minutes. So, the fast is postponed to March 3? Thank you.

You have the wrong moonrise time. I am not an expert, of course, but isn't this rule only typical for the 11th lunar day? Tomorrow is the 26th?

Yes, you are right, the moonrise time today is at 06:48. But the difference from sunrise is still not 96 minutes. For observing the Ekadashi vows, the 11th or 26th lunar day that began before Brahma-muhurta (Arunodaya), that is, at least 96 minutes before sunrise, is considered auspicious. If the 11th or 26th lunar day begins during Brahma-muhurta or after sunrise, then it is recommended to observe the fast not on this day, but on the next, already on Dvadashi (12th or 27th lunar day). There are several more reasons, which are less common, and due to which the fast is postponed to Dvadashi; in this case, such a 12th or 27th lunar day is called Maha-dvadashi. These reasons are related to the time of sunrise and moonrise, to the special days of the new moon and full moon, and to the location of the moon in certain constellations of the lunar zodiac. There are eight such Maha-dvadashi options in total. In different traditions, these days sometimes do not coincide; some people observe the fast precisely on the 11th or 26th lunar days, regardless of whether Ekadashi overlaps with sunrise in a given region or not, and regardless of other astrological reasons.