Subtitle Zero — Dark Thirty

: Military operations often begin during this window to utilize the cover of darkness and the element of surprise. Significance to the Film

The title replaced the initial working title, Kill Bin Laden . It was chosen for its thematic depth: subtitle Zero Dark Thirty

In military slang, "Zero Dark Thirty" refers to an unspecified time in the early morning hours, typically between midnight and dawn. : Military operations often begin during this window