In my previous post on the important festivals for August 2009, I had mentioned 13th August as Janmashtami day. Like so many other customs and rituals, people from different parts of India celebrate Janmashtami on different days. This year too, while most people celebrated Janmashtami on 13th August, some people celebrated Janmashtami on the 14th. Even in south India it is usual that the Vaishnavites and Saivites celebrate the festival on consecutive days.
At the famous Sree Krishna temple at Guruvayoor in Kerala, the festival is being celebrated on the 11th September, one month from now. The reason for this being that the birth of Lord Krishna is celebrated on the Ashtami Rohini day in the month of Chingam in Kerala. As I have explained before, some festivals are celebrated when a particular star (nakshathra) and thithi (the lunar calendar day) fall on the same day like Thiruvathira, Thrikarthika, ChitraPournami, etc. In the malayalam month of Dhanu, the Thiruvathira star falls on the full moon day and Thiruvathira festival is celebrated on that day. Similarly in the malayalam month of Vrischikam, the Karthika star falls on a full moon day and Thrikarthika festival is celebrated on that day. Likewise, legend has it that Lord Sree Krishna was born in the month of Chingam (Shravana) on Rohini Nakshthram and Ashtami thithi (the eighth day in the lunar calendar after the full moon day). The Malayalam era follows the Solar calendar and month of Chingam begins this year only on the 17th August. In the month of Chingam, Ashtami and Rohini fall on the same day on September 11th and hence the festival of Lord Krishna's birth will be celebrated on this day in Guruvayoor temple and elsewhere in Kerala.
However for people observing the Lunar calendar, the month of Shravana began on the 22nd July, 2009, the new moon day, and hence Janmashtami was celebrated on the Ashtami after the full moon day of Shravana month.
As Krishna was born on Rohini nakshathra and killed his maternal uncle Kamsa, there is a belief in Kerala that birth of a boy baby on Rohini nakshathra is not a good omen for the maternal uncle.