Nirvana Day (also known as Parinirvana day) an important day in the Buddhist Calendar. It is the festival celebrated by Buddhists on either 8th or 15th February. It is a celebration of Buddha's death at the age of 80, when he reached total Nirvana. 

What is Nirvana

Nirvana is believed to be the end of the cycle of death and rebirth. Buddhism teaches that Nirvana is reached when all want and suffering is gone. “The Buddha said: "One who is willing to attain Nirvana, has to understand Four Noble Truths. These Noble Truths are the key to attain Nirvana, without proper understanding of Suffering, Cause of Suffering, Relief of Suffering and the way to end Suffering, These are the four Noble Truths." Which are the basic tenants of all forms of Buddhism.
If all suffering is banished then there is no longer any want and if you no longer "want" anything then you automatically have reached a state of peace. People celebrate by meditating and reflecting on their lives and how they can work towards attaining the peace of Nirvana. They spend time remembering family and friends who have died and reflect upon how death is such an intrigal part of life for everyone. If possible they also attend a Buddhist temples or monastery.

In monasteries Nirvana Day is treated as a social occasion. Food is prepared and some people bring presents such as money, household goods or clothes. People also spend a lot of time reflecting about their lives and how they can work towards gaining the perfect peace of Nirvana.

The idea that nothing stays the same is central to Buddhism. Buddhists believe that loss and change are things to be accepted rather than causes of sadness.