On 11 April 2024, the third day of the third lunar month, queues formed at Hanoi markets for bánh trôi and bánh chay used during the Cold Food Festival. At Dịch Vọng market in Cầu Giấy, a 32-year-old woman waited 15 minutes from early morning to buy twenty boxes for family and colleagues. Vendors prepared through the night, but before 9 a.m. demand sometimes outpaced cooking and some customers abandoned crowded lines. One seller reported moving more than 200 boxes in four hours after opening at 5 a.m.
Because these cakes are prepared once a year as offerings to ancestors, even stalls normally selling fruit or savoury foods switched products for the day. The line was more than a fashionable-shop phenomenon: for one morning, the city market became a temporary production system carrying out domestic ritual preparation at scale.