It soon proved uneconomical to stay open 24 hours a day.

每天24小时营业很快就证明是不经济的。

《牛津词典》

The shop is open 24 hours a day.

这个商店24小时都营业。

youdao

You're open 24 hours a day, seven days a week?

你们一天24小时一个星期里的七天都开门吗？

youdao

Unlike other European public transit systems, it stays open 24 hours a day, seven days a week.

BBC: Subway systems by the numbers

Open 24 hours, its dark, loungy interior hosts many faces from the country's celebrity magazines.

NPR: Russian Oil Boom Fuels Rise of the Super-Rich

Superama supermarkets, which are open 24 hours and make home deliveries, serve middle- and upper-income customers in urban areas.

FORBES: It's Nice To Be Big