Second (s)
Definition: Second na SI base unit for time. Dem define am with radiation frequency of cesium-133 atoms.
History/origin: Dem first take second from day, but for 1967 dem redefine am with atomic definition to get better precision and stability.
Current use: Seconds dey used everywhere for science, engineering, computing, sports, finance, and everyday life.
Year (yr)
Definition: Year na long calendar unit based on Earth solar orbit. For unit conversion, dem dey commonly average am as 365.25 days.
History/origin: People organize years around seasons, planting cycles, and sky observations, then dem refine am through calendars for civic and scientific use.
Current use: yr dey used for ages, anniversaries, mortgages, warranties, leases, climate averages, school grades, investment horizons, history timelines, and long-term records.