A young man was engaged to his cousin Kate, but they could not marry without the consent of her guardian, the young man's granduncle Rumgudgeon.
The old man was known for his stubbornness and bizarre superstitions, and he refused to give his consent until three Sundays came together in a week.
You shall have my consent—and the plum, we mus’n’t forget the plum—let me see! when shall it be? Today’s Sunday—isn’t it? Well, then, you shall be married precisely—precisely, now mind!—when three Sundays come together in a week!
The young couple was desperate, as they had to wait for five years to access Kate's inheritance without her guardian's consent.
One day, two naval acquaintances of Kate's, Captain Pratt and Captain Smitherton, visited the young couple and their granduncle. During the conversation, it was revealed that both captains had been away for exactly one year, but they had traveled in opposite directions around the globe. This led to a disagreement about which day was Sunday, as each captain had experienced a different day as Sunday due to their travels.
Kate cleverly pointed out that this meant three Sundays had come together in a week, as Captain Smitherton believed the previous day was Sunday, the young couple and their granduncle believed the current day was Sunday, and Captain Pratt believed the next day would be Sunday.
Thus, with me, yesterday was Sunday—thus, with you, today is Sunday—and thus, with Pratt, tomorrow will be Sunday. And what is more, Mr. Rumgudgeon, it is positively clear that we are all right.
Captain Smitherton explained the phenomenon by describing how traveling east or west around the globe affected the perception of time, and that all three perspectives were equally valid.
Upon realizing that three Sundays had indeed come together in a week, the granduncle finally agreed to give his consent for the young couple's marriage, as he was a man of his word. The young couple was overjoyed, and the granduncle went to consult with his friend, Doctor Dubble L. Dee, about the extraordinary occurrence.