Shop owners are preparing for the new alcohol restrictions that kick in on April 1, when they will begin locking up fridges and covering bottles and cans.
A law was passed in January to tackle the rise in alcohol-related offences by banning the takeaway sale of alcohol from 10.30pm and making it illegal to drink in public places from 10.30pm to 7am.
In Geylang and Little India, part of a designated Liquor Control Zone, shopkeepers expect to be hit harder.
They said they have received police letters instructing them not to sell alcohol after 7pm on weekends, public holidays and the eve of public holidays. They expect to lose thousands of dollars a night on weekends as a result of the laws.
Mr Aristo Loganathan, 29, owns the Big Gainer provision store in Geylang, which is mainly frequented by foreign workers.
"Many customers aren't aware of the ban," he said. "They will spend five, 10 minutes holding up the queue, asking us to give them alcohol. The weekend is good business. I am going to lose about $1,500 to $2,000 in sales a night."
Another store, Budget Value, has made signs stating the new alcohol retail hours, while Thai minimart Peng Tai will cover bottles of alcoholic drinks on its shelves.
The owner of healthcare and provision store Min Sheng He, who gave his name only as
Mr Ong, will begin closing an hour earlier at 10pm. He said in Mandarin: "Selling alcohol is troublesome. If customers know the alcohol is there, of course there will be arguments if you won't sell it. I don't want the trouble."
For Yeo Buan Heng Liquor Shop in Little India, which can currently sell alcohol up to midnight on weekdays and 8pm on weekends, the earlier cut-off times are a further blow to the struggling business.
Its owners, siblings Irene Yeo, 54, and Yeo Eng Hock, 56, expect additional losses of $200 on weeknights.
At nightlife hot spot Robertson Quay, provision shop The Rivergate Grocer has informed regulars about the ban for the past month. It will also put up a sign.
Its manager, who gave her name only as Anna, 47, said it is often frequented by young people who buy alcohol to drink before going to nearby nightclubs. She added: "There's a time stamp on the receipt, so there's evidence (if we break the law)."
The shop is currently allowed to sell alcohol until 2am, though its transactions after 10.30pm account for about 30 per cent of its total alcohol sales.
Meanwhile, posters and signs displaying the new laws will be put up at supermarket chains FairPrice, Sheng Siong, Cold Storage and Giant, as well as convenience stores 7-Eleven and Cheers.
FairPrice included a reminder in its weekly advertisement in The Straits Times last Thursday.
Dairy Farm, which owns Cold Storage, Giant and 7-Eleven, is training staff to deal with alcohol-related problem behaviour. It is also modifying cash registers to block alcohol sales after 10.30pm.
A spokesman estimated that alcohol sales at 7-Eleven stores will fall by 30 per cent. The impact is likely to be less significant on supermarkets as they have shorter operational hours.
Anyone found guilty of drinking after 10.30pm in a public place can be fined up to $1,000, and repeat offenders may be jailed for up to three months.
A shop selling alcohol after the permitted hours may be fined up to $10,000. Those who flout rules in Liquor Control Zones will face 1-1/2 times the applicable penalties.