Hari Raya Puasa is the festival for Muslim to celebrate breaking of the fast.
The names of the months of the Muslim calendar are as follows:
Muharram, Safar, Rabi-ul-Awwal, Rabi-ul-Sani, Jamadi-ul-Awwal, Jamadi-us-Sani, Rajab, Sha'aban, Ramadhan, Shawwal, Dhul Qu'adah, Dhul Hijjah. Muslims observe the fast at the ninth month of their calendar, Ramadhan. It is a practical requirement of the faith and is regarded as an act of devotion. They believe that fasting is prescribed for them so that they may guard against evil. It is regarded as a physical, moral and spiritual discipline for the purpose of promoting righteousness.

A person who is observing the fast is required to abstain from food and drink from the first flush of dawn to sunset, each day throughout the month of Ramadhan. The fast is obligatory upon every healthy, adult Muslim, male or female. There are certain exemptions. A sick person, a person who is travelling, a pregnant woman or one who is breast-feeding her child, one who finds the severity of the fast hard to bear on account of age or other infirmity, are exempt from observing the fast. The person, who is exempt from fast, if he can afford, should arrange to provide food for a poor person throughout the month of Ramadhan, or give the equivalent amount to charity known as FIDYA.

The Muslim calendar is a lunar calendar and the 29th/30th days month of Ramadhan comes eleven days earlier every year. It may therefore, over a period of years, fall in different seasons, unlike the period of religious fasting observed by Christians called LENT which always falls in spring.

The fast places everybody, rich and poor alike, on the same level.
The well-to-do experience the pangs of hunger and thirst in the same manner as their less favoured brothers and sisters. As such, hunger and privation cease to be mere expressions and become an experience shared in common. The result is that they become more sympathetic to the needs of the poor.
Fasting is an excellent means of curing obesity and problems relating to over-weight.
Fasting is also believed to develop will-power and curb bodily desires and habitual self-indulgences.

During the month of fasting, there are festival markets in Geylang Serai and Kampong Glam.

Many Muslims go to Geylang Serai to have their festival shopping. Many non-Muslim Singaporean and tourists also like to visit the market for goods with traditional Muslim culture. A wide variety of Malay foods can also be found in the Kampong Glam festival market.