Whence the 8th Day of the 4th Lunar Month as the Buddha’s Birthday

Two dates, the 8th day of the 4th lunar month (Date A) and the 8th day of the 2nd lunar month (Date B), are found in Chinese Buddhist translations as the Buddha’s birthday. However, how to understand the simultaneous existence of both of these dates remains an unresolved problem. This paper proposes a rather new interpretation to try to solve this puzzle, and provide an answer to the question: whence the 8th day of the 4th lunar month as the Buddha’s birthday? It is argued that: (1) The date of the Buddha’s conception and the date of his birth were both translated variously as Date A or Date B in early Chinese Buddhist literature. However, many later texts referring to the Buddha’s birthday do not include reference to an auspicious junction star (puṣyanakṣatra), which is critical for understanding these dates; (2) Both the Indian and Chinese traditions regard an individual’s life to begin at the moment of conception; therefore, the so-called Buddha’s birthday could be argued as the date of his conception; (3) The date of conception of the Buddha was specified as the 8th day of the śuklapakṣa of the month Vaiśākha, the day of the vernal equinox. This corresponds to Date A in the Chinese Xia calendar.