Vesak Day (卫塞节), is a celebration in the Month of May on the day of Full Moon, commemorating the birth, enlightenment and attainment of nirvana of Siddharta Gautama Shakyamuni (Sakyamuni) Buddha. This time of joy, peace and reflection is celebrated by Buddhists in Singapore and over the world.
The move to make Vesak Day a public holiday only started after World War II. According to Ong Y. D., the first of many petitions to the government to make Vesak Day a public holiday was from the Singapore Buddhist Association in October 1947. It was only in June 1955, after David Marshall’s Labour Front government had come to power, that Vesak Day was made a public holiday in Singapore.
Highlight of Vesak Day – The Waters of Life
‘Bathing’ of the Buddha is one of the most popular rituals carried out on Vesak Day.
There will be a small central elevated statue of the child Siddhartha, placed in a basin or pool decorated with garlands of flowers. Worshippers will use a ladle to scoop water from the basin and pour it over the statue, in remembrance of the legend that the infant prince was showered with the waters of nine dragons soon after he was born.
Offerings & Doing Good Deeds
Worshippers will also bring flowers, candles and joss sticks to temples as offerings. It is said that the meaning behind the fact that the candles and joss sticks burn down and the flowers wither is to remind all worshippers that life is fleeting and evanescent, that all things will end someday.
The rest of the day is spent on worthy causes, as devotees believe that performing good deeds on Vesak Day will multiply your merits. They will only eat vegetarian meals even though charities and blood donation drives are organised, or some spend hours chanting mantras.
Candlelight processions
Statues of the Lord Buddha are illuminated on Vesak Day and the day often ends with candlelight processions through the streets. Devotees will practice the two-hour-long ‘three-step, one-bow’ ritual, taking steps on both knees, bowing at every third step as they pray for world peace, personal blessings and repentance.
Every year, a Vesak Day Blessing Event will be held at Nirvana Memorial Garden.
References:
https://www.un.org/en/observances/vesak-day
https://www.visitsingapore.com/festivals-events-singapore/cultural-festivals/vesak-day/
https://eresources.nlb.gov.sg/infopedia/articles/SIP_242_2004-12-30.html
English 
Chinese