The temporal span covered by the narrative — seconds to decades. Independent of actual runtime.
The story time is the central temporal framework of your narrative—the span of time within which the plot actually unfolds. A film can run for 90 minutes and still tell a story that spans 20 years. Or vice versa: 120 minutes of runtime for 48 hours of plot. This is the crucial distinction between story time and film time (runtime). This distinction determines your entire dramaturgical architecture.
On set, you notice this immediately during preparation: if you're telling a story that unfolds over a single night, you'll need a different continuity, different lighting setups, and different acting than a story spanning decades. In 12 Angry Men, the story time almost corresponds to the film time—90 minutes of film for approximately 90 minutes of plot. This creates intimacy and immediacy. In contrast, in Forrest Gump, the story time encompasses an entire lifetime. The film must compress this through montage, scene changes, and character aging—this is compression montage. Conversely, there is also expansive storytelling: when you show a scene where practically nothing happens, but the story time is short and the film time is long—this is deliberate temporal dilation that builds tension or creates significance.
This is crucial for planning: you need to know whether you are omitting moments (which implies that time is passing) or whether you are showing everything linearly. The story time also structures how much ellipsis and dissolve you need—or whether you are working in real-time. If your story spans three months, you can't shoot everything. You choose dramaturgical highlights, skipping over insignificant days. This is classic craftsmanship: the story time is your raw material, your film runtime is your rationed resource—you must decide which parts of the story time you make visible and which you do not.