It may be 6.30am on a Sunday but the Pang family is up and about, sweeping and picking up other people's litter.
Fund manager Pang Cheng Duan, 49, his wife Theresa Wee and their 11-year-old daughter Sze Ann are armed with brooms and dustpans, hunting down stray pieces of trash at the public carpark outside Eunos MRT station.
They attract curious stares from onlookers and have even been mistaken for offenders doing community service.
The Pangs are part of a group of volunteers from Shinnyo-en Singapore. For nearly 30 years, this religious organisation - a 4,000-strong local chapter of a Buddhist order in Japan - has been cleaning public spaces early in the morning. Every fourth Sunday of the month, between 60 and 100 of its volunteers clean up MRT carparks around the island.
Keeping the environment clean is their contribution to society, said volunteers, including 63-year-old retiree Tan Yen Seng, a litter-picker for 10 years.
Agreeing, entrepreneur Michael Tasrif, 29, said: "As people living in Singapore, we have the responsibility to keep our country clean,"
The group first began cleaning Clifford Pier once a month in 1983. Six years later, it started cleaning the void decks of HDB flats in Farrer Road.
Since 1994, with approval from the National Environment Agency, it has been cleaning the surrounding areas of the Clementi, Ang Mo Kio and Eunos MRT stations, because many of its members were living around there. They keep each session short so as not to get in the way of residents and commuters, said Madam Wee, a 47-year-old housewife.
Public reactions vary. Most people stare, some ask what they are up to, while others thank them for their work.
Madam Wee's daughter Sze Ann, a Tao Nan pupil, said it is a meaningful task and she is happy to do the cleaning. They sometimes collect several bags full of rubbish and salvage recyclables.
Said Madam Wee: "We hope our little effort can go some way towards changing Singaporeans' mindset and attitudes, and that Singapore will one day become a clean city because our people take pride in keeping it clean."
The volunteers, mostly in white shirts with the Shinnyo-en logo, gladly go about their labour despite having to sacrifice sleep each last Sunday of the month.
"I'm not an early bird," admitted civil servant Han Fei Ni, who is in her late 30s. "But it's gradually become a habit I enjoy because it's a good cause."
For more information on the group and its activities, go to www.shinnyoen.sg