Sekunnin

Sekunnin is the genitive singular form of sekunti, the Finnish word for the unit of time equal to one second. It is used to indicate possession or association with a second, and appears in time expressions such as sekunnin kuluttua (“in a second”), sekunnin aikana (“during the second”), or kahden sekunnin päästä (“two seconds later”). In compound phrases, sekunnin often acts as a descriptive element, for example kolmen sekunnin ajan (“for three seconds”) or kahden sekunnin välein (“at two-second intervals”).

Sekunti is the SI base unit of time. Its symbol is s. The current definition ties the second to the fixed frequency of the cesium-133 atom: exactly 9,192,631,770 periods of the radiation corresponding to this transition. This definition, adopted in the mid-20th century and refined in subsequent updates, provides a precise and universally reproducible standard for measuring time.

Etymology and linguistic notes: sekunti originates from Swedish sekund, which itself comes from the Latin secundus, meaning “second.” In Finnish, the word adopted its inflected forms, including sekunnin in the genitive, to allow phrases that express durations, intervals, and relations to time.

Usage overview: in ordinary Finnish, sekunti is used for counting time and durations (one second, two seconds, etc.), with plural use of sekuntia in the accusative for direct durations (kaksi sekuntia). The genitive sekunnin appears in constructions that describe a quantity or interval before a noun (kolmen sekunnin kuluttua, sekunnin välein) and in other phrases where possession or a defining relationship to a second is expressed. Related terms include millisekunti (millisecond) and pikosekunti (picosecond).