Dear Maharaj:
Pamho. AgtSP. Hare Krsna!
1. You're right, I am new to the Vedic calendar. However, I'm not new to naked eye astronomy which has been my favorite science since childhood.
2. I discovered these errors quite unexpectantly; moreover, I couldn't believe it myself that so many people could miss this but now I understand why.
3. First off, I was puzzled that the particulars of the Lord's birth in Phalgun, Sakabda 1507 didn't seem reflected consistently by our Vaisnava calendar. Second, it wasn't until I could understand the present method of calculation that I was confident of my conclusions. The present method is the one followed by the Indian National Calender with respect to the national Hindu holidays. The present method of calculation makes sure that every lunar year begins after the vernal equinox (Mar 20/21), instead of simply following the astrological sign of Pisces to determine the start of the new year. In additon, there is a strong sentiment in India amonsgt the so called educated to rid Indian of it's passion for astrology, so therefore, the equinox is favored over the sidereal Sun sign.
4. Next, the topic of the Hindu lunar calendar is very complex. So, it's very easy to see why anyone in Iskcon would miss this. Moreover, it's easy to see why the whole Vaisnava community chooses to accept the national dates. Afterall, who would want to buck the national standard; unless, of course, that person was absolutely sure of what they were doing. I'm becoming quite knowledgeable on this topic. I have already spent 100's of hours research on this topic.
5. I have already pointed out that this change can be pinpointed to 1957 when the Indian government adopted and set the standard for the Saka calendar. Prior to that the Sri Caitanya Math determined the correct dates. Since any knowledgeable person knows about the precession of the equinox, it would be easy over time with each new generation of devotees to miss this point about the Lord's birthday and other errors regarding the lunar calendar.
6. Also, as a result of this enquiry, I have been able to completely cracked the mystery of the 27/28 nakshastras of the Vedas but I will go into this in the near future.. As I pointed out in the beginning, change will happen slowly and for some it will never happen. My plan is simply to present the facts and hope the reader will become educated on this topic.
7. In closing for now, it is amazing what this research has revealed to me about dating in the Vedas, etc. Also, the astrology community doesn't really have a vested interest in this historical aspect. What they do works perfectly well for today's birthdates and horoscopes.
YHS, Saranga Thakura das
HpS -ASA - AGTSP!!!!! Still no handles for us laymen! Do you mean that Gaura purnima is the purnima one month earlier than the one we celebrate?