twenty-four seven

All day, every day. Short for "twenty-four hours a day, seven days a week." Another hyphen can be used between "four" and "seven" if used as a modifier before a noun. Often written as 24/7. You know you can call me twenty-four seven if you ever need anything, OK? It's the only shop in the entire city that's open 24/7. We offer twenty-four-seven customer support for anyone whose credit card is lost, stolen, or locked.

twenty-four/seven

Also 24/7. Indication that something—a store, a service, a person—is available at all times (twenty-four hours a day, seven days a week). Used since the second half of the 1900s, at first for shops that never close, the term was soon applied in numerous other contexts. For example, “I’m not looking to get a knife in my chest. I’ve got twenty-four/seven protection on me” (David Baldacci, Hour Game, 2004). A theater review by Ed Siegel in the Boston Globe (Feb. 1, 2005) also had it: “The younger generation. What are we to do with them, with their ‘whatever’ attitude, their irony, and their 24/7 access to sex, drugs, rock’n’roll, and the Internet?” See also whatever.