The Great Singapore Sale (GSS) starts on June 9 but some retailers have jumped the gun.
Department stores Robinsons and Metro, furniture store HomesToLife, and baby supplies stores Mothercare and Kiddy Palace have already started offering mid-year promotions.
Mothercare's managing director, Mr Pang Fu Wei, said holding the sale early to beat competitors yielded "very positive results" last year. Its sale this year runs for eight weeks, from May 17 to July 16 - two weeks longer than last year's.
"It's been 1½ weeks so far and the response has been positive. We hope the momentum will continue," said Mr Pang.
HomesToLife general manager Phua Bo Wen said it brought forward its GSS promotions because customers asked about mid-year bargains after it launched a new sofa collection last month.
The store is offering a 20 per cent discount on all sofas and 30 per cent off on all carpets. Customers can sign up as members on the spot to receive an additional 5 per cent discount.
HomesToLife, which has two outlets, has slashed prices by half for selected furniture items.
GSS used to start in May, but the organiser, the Singapore Retailers Association (SRA), wanted to align it with the holiday season in key visitor markets such as Indonesia and China.
The nine-week sale ends on Aug 13 - after National Day on Aug 9 - which allows retailers to hold National Day-themed promotions as part of GSS, said the SRA.
The association noted that most locals would have returned to Singapore by the second half of next month's school holidays, and would be able to participate in the sale.
This year, GSS is going digital with a free mobile app called GoSpree, which offers e-coupons to shoppers. The geolocation-enabled app will also let retailers send e-coupons and flash-deal alerts to shoppers nearby.