Final answer:
The text of 'Into the Wild' by Jon Krakauer does not provide a specific birthday for Franz, and therefore it can't be determined from the information given in the book or the related literature.
Step-by-step explanation:
The question focuses on a detail from Jon Krakauer's narrative nonfiction Into the Wild, specifically the birthday of the character Franz. However, Into the Wild does not specify the birthday of Franz, who is one of the people Chris McCandless (the protagonist of the story) encounters during his journeys.
This detail might not be directly available in the text itself, or in the works frequently cited alongside Krakauer's narrative such as Henry David Thoreau's Walden. If a birthday for Franz is needed for analysis or comparative purposes, one may have to infer or approximate based on other contextual clues provided in the narrative.
Since the text does not clearly offer this information, we cannot provide a date for Franz's birthday.