Definition & Meaning of "Cinderella liberty"in English

What does "Cinderella liberty" mean in military slang?

The structure combines "Cinderella" (the fairy tale character who had to leave the ball by midnight) with "liberty" (military term for authorized leave), forming a noun phrase that evokes a magical but time limited escape. It is used to describe a period of leave or pass that ends at midnight, requiring service members to return to base or quarters before the clock strikes twelve. People typically use the term in naval and military contexts, warning that "Cinderella liberty" is shorter and stricter than full weekend leave.