The title refers to a popular expression used to justify drinking at any time of day, given that somewhere in the world it's 5:00 p.m. (the end of the work day for a traditional "nine-to-five" worker). The narrator states that he hasn't had a day off in over a year and that he wants to leave work and relieve his stress by drinking alcohol. The lyrics include the phrase, "It's only half-past twelve but I don't care. It's five o'clock somewhere", which means that even though it is not five o'clock in the narrator's time zone, it must be in another part of the world. 5 p.m. is typically the start of 'Happy-Hour' at most restaurants and bars.