kolmena
Kolmena is a grammatical form in Finnish that derives from the numeral kolme (three). It is used with time-related nouns to express a span or distribution across three units, typically in more formal or idiomatic contexts. The form is most commonly encountered with the adessive case on the time noun, indicating a duration or period that covers three units, such as days or months.
In use, kolmena often appears in phrases that translate roughly to “over three days” or “during three
Limitations and notes: kolmena is not universally required or productive with all time nouns, and its appropriateness
See also: Finnish language, numerals, grammatical cases, time expressions.