Which unit represents time in the International System of Units (SI)?

The unit that represents time in the International System of Units (SI) is seconds (s). The International System of Units is a globally accepted metric system that standardizes measurements across various fields including science, engineering, and education. In this system, the second is the base unit for time, defined as the duration of 9,192,631,770 cycles of radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom.

While minutes and hours are commonly used to measure time in everyday life, they are not base units in the SI. Instead, they are derived units; minutes consist of 60 seconds, and hours consist of 60 minutes, which translates to 3,600 seconds. Milliseconds, though useful in specific contexts like scientific experiments or computer processing, represent one-thousandth of a second and are therefore also derived from the base unit of seconds. Thus, the most precise and fundamental representation of time according to SI standards is seconds.