It is said that "Happy hour" entered civilian use in the 1960s. About fifty years ago, one of the bars in New York put up a note on the window, saying that everyday from 5 p.m. to 6 p.m. would be the "happy hour" of the bar when drinks would be sold at half price. It soon attracted many people who were on their way home after work, and the bar business grew rapidly.
据说，"Happy Hour" 一词大约20世纪60年代开始在民间盛行。约50年前，纽约一家酒吧的玻璃橱窗上贴了一张广告，说本店每天下午5点到6点定为"Happy Hour"， 在这段时间内半价出售饮料。这张广告立即吸引了下班回家的人群，酒吧的生意也迅速攀升。
Happy Hour soon became a marketing promotion term for a restaurant or bar to boost business by offering discounts on alcoholic drinks. Usually, it takes place in the late afternoon Monday through Thursday at some period between 4 p.m. and 7 p.m.. In most cases the "happy hour" lasts longer than a single hour.
"Happy Hour" 一词很快成为一个市场促销用语。餐馆及酒吧为了推动生意便 采取减价出售酒精饮料的方式促销。通常，"快乐时光"在周一至周四的下午4点和7点之间进行，一般不止持续一小时。

The specifics usually differ from country to country. For instance, in Holland, the price of an alcoholic drink is regulated and it is prohibited to sell them at half price. During happy hour, a customer gets double the amount of drinks instead. In Italy, a customer often pays the same price or even more for the drink but is offered free finger foods. And in the United States, customers are offered finger foods as well as discounted drinks.
各个国家的政策也不尽相同。比如，在荷兰，酒精饮料的价格是统一的，不准半价出售。这时，顾客可以在"快乐时光"里花一份钱得到两倍数量的酒。在意大利. 顾客通常要付同等或稍高的价格，但是会得到免费的小点心。而在美国，消费者不仅能得到免费小点心，还能享受折扣饮料。
Nowadays, the term is commonly used to describe the gathering of work colleagues at a restaurant or bar after work hours, possibly outside the period of 4 p.m. and 7 p.m. In universities such as Yale, the term is widely used to refer to the gathering of students for parties. There is weekly "happy hour" in Law School, with all the things free.
如今，"快乐时光"泛指同事们在工作之余的饭馆或酒吧聚会；这种聚会很可能是下午4点至7点之外的时间段。在诸如耶鲁这样的大学校园里，这个词也被广泛用于指代学生聚会。耶鲁法学院就有每周一次的"幸福时光"；不过，法学院的所有饮料和食物可都是免费的。