Bilbo and Frodo Baggins are both said to have birthdays on 22 September in J.R.R. Tolkien’s fiction. Bilbo was born on that date in T.A. 2890, and Frodo was born on it in T.A. 2968.
The shared birthday is one of the links between the two hobbits. Bilbo celebrates his eleventy-first birthday at the beginning of The Lord of the Rings, while Frodo’s twenty-ninth birthday occurs on the same day. Bilbo’s party becomes the setting for his dramatic departure from Hobbiton.
The date is also Tolkien’s birthday in the Gregorian calendar’s day-and-month form only by coincidence: Tolkien was born on 3 January 1892. The fictional date should therefore not be used as the author’s birthday.
In Tolkien’s world, dates can be expressed using calendars such as the Shire Reckoning and the Kings’ Reckoning. The day and month 22 September remain the familiar modern presentation for the birthdays of both Baggins characters.