Magha Puja Day is one of the most important Buddhist celebrations which falls on the full moon day of the third lunar month (about last week of February or early of March).
This day marks the great four events that took place during Lord Buddha's lifetime, namely;
1.1250 Buddhist monks from different places came to pay homage to Lord Buddha at Valuwan Vihara in Rajgaha, the capital of Magaha State, each of his own initiative and without prior notification or appointment.
2.all of them were the enlightened monks (or Arahantas)
3.all of them had been individually ordained by Lord Buddha himself (Ehi Bhikkhu)
4.They assembled on the full moon day of the third lunar month.
On the evening of that day, Lord Buddha gave the assembly a discourse "Ovadha Patimokha" laying down the principles of His Teachings summarised into three acts, i.e. to do good, to abstain from bad action and to purify the mind.