Seconds (s)
The second, symbol s, is the fundamental base unit of time in the International System of Units (SI). Historically defined as 1/86,400 of a mean solar day, it was redefined in 1967 by the 13th General Conference on Weights and Measures based on atomic properties: exactly 9,192,631,770 periods of radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom. It serves as the baseline for defining many other physical units.
- Years3.17×10⁻⁸
- Months3.8×10⁻⁷
- Weeks1.65×10⁻⁶
- Days1.16×10⁻⁵
- Hours2.78×10⁻⁴
- Minutes (minute)0.02
- Seconds (s)1
- Milliseconds (ms)1,000
- Microseconds (µs)1,000,000
- Nanoseconds (ns)1,000,000,000