1. Introduction
2. Materials referring to Sakyamuni's age when he renounced the world
3. Materials referring to Sakyamuni's age when he attained enlightenment
4. Materials referring to Sakyamuni's age when he entered parinibbāna
5. Lines of tradition concerning Sakyamuni's renunciation, enlightenment and parinibbāna
6. Calculation of Sakyamuni's age according to full years or by traditional reckoning
7. Sakyamuni's birth, renunciation, enlightenment and parinibbāna according to early Pali writings
8. The day and month of conception
9. The day and month of birth
10. The day and month of the renunciation
11. The day and month of the enlightenment
12. The day and month of the parinibbāna
13. Sakyamuni's age at his birth, the renunciation, enlightenment and parinibbāna and their day and month according to other documentary materials
14. Lines of tradition concerning the day and month of Sakyamuni's conception, birth, renunciation, enlightenment and parinibbāna.
15. Conclusion

Sakyamuni, age at renunciation, age at enlightenment, parinibbāna, date of birth, age in full years, age by traditional East Asian reckoning, conception, birth, Vesakha


 There is no agreement regarding Sakyamuni's age at, and the specific dates of, the important turning points of his life among the many opinions existing in both the Southern tradition of Sri Lanka, Burma and other areas of Southeast Asia, and the Northern tradition that was transmitted to China and disseminated through Chinese translation. Furthermore, the question remains open whether the age given for the major events of his life was calculated in full years, as is the European custom, or by the traditional reckoning, where a child is considered to be one year old at birth. Japanese high school textbooks, for example, give the Buddha's dates as ca 463-383 BCE. This calculation appears to be based on the tradition that Sakyamuni was eighty when he died around 383 BCE. Obviously it was made on the assumption of eighty "full" years. However it is highly doubtful whether or not this assumption was made according to any independent confirmation. Also, if Sakyamuni's age is considered in terms of full years, problems arise concerning the dates of his birth and death. Consequently I do not think the calculation was based on any kind of scholarly investigation.

 This study has as its objective the creation of a chronology of Sakyamuni's life, and so the points raised above cannot be dismissed without further investigation. It gathers together all the traditions concerning Sakyamuni's birth, renunciation, enlightenment and parinibbāna, beginning with descriptions from the early Pali texts, and then analyses and classifies them in an attempt to confirm ages and dates for these important milestones that are the basis for any chronology of the Buddha's life. This paper reveals that the Buddha's age has been counted in full years, based on a date of birth that actually refers to his conception. Accordingly, the ages and dates of the key events in Sakyamuni's life are as follows:

1. Sakyamuni's age has been reckoned in full years, from his conception on the day of the full moon in the āsāḷhā month (4.15 according to the Chinese calendar). 
2. He was born at the "age" of ten months on the day of the full moon in the vesākhā month (2.15 according to the Chinese calendar). 
3. The renunciation occurred at the age of 29 years on the day of the full moon in the āsāḷhā month (4.15 according to the Chinese calendar). That is, it occurred on his 29th birthday. 
4. The enlightenment occurred at the age of 35 years and 10 months on the day of the full moon in the vesākhā month (2.15 according to the Chinese calendar). His period of asceticism thus lasted 6 years and 10 months.
 5. His parinibbāna occurred at the age of 80 years and 10 months on the day of the full moon in the vesākhā month (2.15 according to the Chinese calendar). He spent his eightieth birthday at the rainy season retreat in the village of Beluva near Vesālī.