Seconds to Minutes (s to min)

The second (s) is the SI base unit of time, defined since 1967 as exactly 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom (the Cs-133 hyperfine transition at 9.192631770 GHz). The 2019 SI redefinition preserved this atomic-clock definition. The recognised SI symbol is "s" (lowercase, italics-disambiguated when needed). The second is the foundational unit for all other SI time-related units (the hertz at 1/s, the becquerel at 1/s for radioactive decay, the SI joule via 1 J = 1 N·m and the metre is defined via the speed of light × the second). Atomic clocks based on the caesium-133 transition currently achieve precision better than 1 part in 10^15, with the most-recent optical-lattice atomic clocks (Sr-87, Yb-171) approaching 1 part in 10^18 precision. The second is preserved unchanged across every modern timekeeping context, scientific publication, and engineering specification.

The second has been preserved unchanged in concept since Babylonian astronomy in the third millennium BC, where the day was divided into 24 hours, each hour into 60 minutes, and each minute into 60 seconds — the sexagesimal time-division system that survives globally today. The modern SI second was redefined in atomic terms at the 13th CGPM in 1967 as "the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom" at zero magnetic field and at rest at 0 K. The atomic-second definition replaced the older astronomical-second definition (1/86,400 of a mean solar day, since 1820) which was based on Earth's rotation rate and therefore subject to the slow secular slowdown of Earth's rotation due to tidal friction. The 2019 SI redefinition preserved the atomic-second definition as the fundamental SI base unit of time, with all other SI units (metre, kilogram, ampere, kelvin, mole, candela) anchored to defined fundamental constants traceable through the second. The second is the SI base unit of time and the universal primary unit across physics, engineering, atomic-clock metrology, GPS, and modern timekeeping.

Atomic-clock metrology and GPS: every modern atomic clock (caesium-fountain primary clocks at NIST, NPL, PTB, NMIJ; optical-lattice clocks at JILA, Riken, NPL) measures time in seconds with precision better than 1 part in 10^15. GPS satellites carry caesium and rubidium atomic clocks for nanosecond-precision timing, with the GPS-time-system traceable to UTC (Coordinated Universal Time) maintained by atomic clocks at BIPM in Paris. Physics-laboratory and engineering measurement: every modern physics-laboratory measurement involving time denominates in seconds for the SI-canonical primary documentation. Particle-physics decay-rate measurements, fluid-dynamics oscillation-period analysis, mechanical-engineering vibration-period analysis, and atomic-physics-spectroscopy lifetime measurements all use seconds. Sports timing and athletic-record certification: every IAAF-sanctioned (now World Athletics) athletics-meet timing system (Hamamatsu Photonics, Omega Timekeeping, Seiko Sports Timing) measures sport-event times in seconds with millisecond precision (Usain Bolt 100m world record 9.58 s; Eliud Kipchoge marathon world record 2:01:09 = 7269 s). Computing and electronics: every modern computer-system clock denominates time in seconds and sub-second multiples (clock cycles at GHz = billion-per-second, system-time in nanoseconds for high-precision events, kernel-time in microseconds for OS scheduling). Sub-second precision is universally required across modern computing systems.

The minute (min) is exactly 60 seconds by SI definition, derived from the Babylonian sexagesimal time-division system preserved unchanged into the modern SI second. The recognised symbol is "min" with no spaces or punctuation. The minute is not part of the SI base units but is recognised by NIST and BIPM as a non-SI unit accepted for use with the SI. The relationship to the second is exact (1 min = 60 s) and the relationship to the hour is exact (1 hour = 60 min). Sub-minute precision uses seconds and milliseconds; super-minute precision uses hours and days. The minute is universally used across timekeeping, sport-timing, athletic-record certification, engineering-process specifications, and casual everyday time references.

The minute as a unit of time has been preserved unchanged from Babylonian astronomy, where the hour was divided into 60 minutes (the sexagesimal "minute" or "first division") and each minute into 60 seconds (the "second" or "second division"). The unit derived from the Latin "minutum" (small) and "pars minuta prima" (first small part), with the parallel terminology preserved across modern Latin-derived languages (French "minute", Italian "minuto", Spanish "minuto"). The minute is not part of the SI base units but is recognised by NIST and BIPM as a non-SI unit accepted for use with the SI in everyday-time-keeping, sport-timing, and engineering contexts. The 1967 SI second-definition transitively defined the minute as exactly 60 seconds, fixed by the atomic-clock primary standard. ISO 80000-3 specifies seconds as the SI-canonical primary time unit but tolerates minutes in commercial-and-everyday timekeeping contexts. The minute is universally used across timekeeping (every clock and watch displays minutes), sport-timing (track-and-field event-times in minutes-and-seconds), and engineering-process specifications (cooking times, manufacturing process cycle times, cardiac-medicine pulse rates).

Everyday timekeeping: every clock, watch, smartphone, microwave timer and oven timer displays minutes alongside hours. Cooking times, microwave times, oven baking times, and casual timing references all use minutes universally. Sport-timing for middle-distance and longer events: track-and-field middle-distance and long-distance events (800m, 1500m, 5000m, 10000m, marathon, ultramarathons) are timed in minutes-and-seconds format, with marathon times reported as e.g. "2:01:09" for Eliud Kipchoge's world record. The minutes-and-seconds format combines the minutes-multiple and seconds-precision for legible event-time reporting. Cardiac-medicine and heart-rate monitoring: heart rate is universally denominated in beats per minute (bpm) across cardiac-medicine, fitness-tracker apps, and clinical-monitoring equipment. Typical resting heart rate is 60-100 bpm; typical max heart rate during exercise is 150-180 bpm. Manufacturing and process-engineering: industrial-process cycle times, manufacturing-line cadence specifications, and process-engineering throughput rates use minutes for the operator-facing process-control documentation. A typical injection-moulding cycle time is 30-90 seconds (0.5-1.5 minutes); a typical CNC-machining cycle is 5-30 minutes; a typical bottling-line throughput is 200-500 bottles per minute.