12s

12s is most commonly used to denote twelve seconds, the base unit of time in the International System of Units (SI). The formal notation places a space between the numeral and the unit: "12 s". In some sources and software, the compact form "12s" appears without a space, though it is less consistent with SI conventions.

In practice, 12 s characterizes a duration. It appears in timekeeping, sports results, experimental protocols, and media contexts—for example, timing a sprint, a stimulus presentation lasting 12 s, or a video clip of 12 s length. In cognitive psychology and neuroscience, reaction times are frequently reported in seconds, including durations around 12 s.

The string "12s" may also arise in non-technical contexts unrelated to time, such as file names, catalog numbers, or shorthand in notes. In such cases the intended meaning should be inferred from surrounding information.

Related terms include the second (the SI base unit of time) and duration as a general concept.