around the clock around 是围绕的意思，clock 是钟表，围绕着钟表不停转，就是 all day and all night without stopping，中文意思就是“夜以继日地”“昼夜不停地”“不眠不休地”。尤其在表示工作繁忙时会经常用这个短语。 Firefighters are working 18 hours a day, around the clock, trying to make sure that they get this blaze under control. 消防员们昼夜不停一天工作18个小时，试图确保火势得到控制。