The Asanha Puja Day is one of the sacred days in Buddhism as it marks the coming into existence of the Triple Gems, namely: the Lord Buddha, His Teachings and His Disciples. The day falls on the fifteenth day of the waxing moon of the eighty lunar month (July). It is an aniversary of the day on which Lord Buddha delivered the First Sermon to his first five disciples at the Deer Park in Benares over two thousand five hundred years ago.
To observe this auspicious day, Buddhists all over the country perform merit-making and obsweve Silas (Precepts). Some go to the temples to offer food and offerings to the monks and also listen to a sermon to purify their minds. The Asanha Puja Day falls on the day preceding the Buddhist Lent which starts on the first day of the waning moon of the eighth lunar month.
The tradition of Buddhist Lent or the annual three-months Ranins Retreat known in Thai as "Phansa" dates back to the time of early Buddhism in ancient India, all holy men, mendicants and sages spent three months of the annual rainy season in permanent dwellings. They avoided unnecessary travel during the period when crops were still new for fear they might accidentally step on young plants. In deference to popular opinion, Lord Buddha decreed that his followers should also abide by this ancient tradition, and thus began to gather in groups of simple dwellings.
Buddhist Lent covers a good part of the rainy season and lasts three lunar months. In Thailand, Buddhist monks resolve to stay in a temple of their choice and will not take an abode in an other temple until the Lent is over.
The celebration of the beginning of Buddhist Lent is marked by the ceremony of presention candles to the monks. Various institutions e.g. schools and universities, including public and private organisations will organise a colourful candle procession leading to a temple where the offering of the candles will be made.
Some Buddhist followers consider the beginning of Buddhist Lent as a time for making resolution such as refraining from smoking or observing five precepts (Panjasila) throughout the three-month Rains Retreat.