A few thoughts on Guru Purnima and the translation of ideas between the East and West. Any day or time is a good moment to worship the Divine. With this in mind, let’s take a fresh look at Guru Purnima from the perspective of those who invented the occasion. Guru Purnima is defined as occurring during the 15th Tithi (Purnima) of the waxing Moon in the lunar month of Sravana with the Moon in the Nakshatra of Sravana. The Sanskrit word “Tithi” is calculated using the longitude of the Moon and Sun. For those interested, please look carefully into the terms, lunar month, Tithi and Nakshatra. The main point I am bringing to light here is that indication and timings for the full Moon as found at NASA or local media is based on the moment in which the Moon is 180 degrees from the Sun relative to Earth. This is the definition of Full Moon. However, the planets are in motion and when the Moon is 180.x degrees from the Sun, the Moon is now waning and no longer called Purnima. The peak has been reached and Guru Purnima has passed. Relative to the Eastern concept of the occasion, the Western date and time of the Full Moon marks the closing moment of the Eastern Guru Purnima.
I personally don’t use the Hindu Festival Calendar much but many are nostalgic about the yearly moments of Guru Purnima, Shiva Ratri and Nava Ratri etc. The Devil is sometimes in the details and plenty is often lost in translation when some concepts are not understood and perhaps simplified due to cultural differences and inattention to details. I thought I would point this out since many sincere people in the West are devotedly observing Guru Purnima after it has already past and concluded. The same confusion abounds for Shiva Ratri. Shiva Ratri is on the 14th Tithi of the waning Moon. When the New Moon occurs it is all over, etc.