viikoista

Viikoista is the plural elative form of the Finnish noun viikko (week). In Finnish grammar, the elative case expresses origin or source, and the plural form viikoista is used when the reference concerns more than one week. It roughly corresponds to "from the weeks" or "of the weeks" in English. The singular counterpart is viikosta ("from the week"), while other related forms include viikot (nominative plural) and viikkojen (genitive plural).

Usage typically arises in contexts that discuss data, time periods, or sources spanning several weeks. Examples: Tilastot ovat peräisin viikoista 12–15. Raportti kattaa viikoista 3–9 kerätyt luvut. Kyselyn vastaukset viikoista 1–4 osoittavat kasvua.

When forming ranges, a dash is commonly used to connect the week numbers (12–15). Viikoista is not used for a single week; for one week the form is viikosta. The elative plural is a standard feature of Finnish noun inflection and appears in journalism, statistics, and academic writing to describe periods, sources, or comparisons across multiple weeks.