Days, Months and Seasons

Days, months and seasons are among the very first words you will need, and they come with two things English speakers must unlearn. First, they are all written lowercase — mandag, januar, vinter, never capitalized — which is the single most common spelling mistake English speakers make in Norwegian. Second, each kind of time-word pairs with a conventional preposition: på with days, i with months, om with seasons. Get the lowercase rule and these three pairings down and you can already talk about your whole calendar.

The days of the week

All seven are masculine nouns (en mandag), so the definite is mandagen and the plural is mandager. The week starts on mandag, not Sunday — calendars, planners, and the word uke (week) all treat Monday as day one. Note the spellings with ø: lørdag and søndag. The names are old: torsdag is "Thor's day," fredag is named for the goddess Frigg/Freya, onsdag is "Odin's day" (Odin = Óðinn/Wōden, the same source as English Wednes-day).

The months

The months are close cousins of the English ones, so they are easy to recognize, but watch the spelling differences: mars (not "march"), mai (not "may"), and desember with an s, not a c. Like the days, they are lowercase and masculine (en kald januar). You will rarely need them in the plural.

The four seasons

Two spelling traps to lock in: vår (spring) has å, and høst (autumn) has ø. Be careful with vår — the same word also means "our" (the possessive), so context tells them apart: en kald vår "a cold spring" vs vår bil "our car." All four seasons are masculine, and all four are lowercase.

The prepositions: på, i, om

This is the part worth real attention, because the preposition is not predictable from English and each time-unit has its own conventional partner. The good news is that the pattern is tidy:

Days take på. "On Monday" is på mandag. Note the contrast with English: English uses "on" for days, but Norwegian på is its own word with no general "on a date" feeling — it just happens to be the day-word partner. For a recurring day, use hver (every): hver mandag, "every Monday," with no preposition at all.

Months take i. "In March" is i mars. This i is the same little word as "in," so it feels natural to English speakers — months are the easy case.

Seasons take om for the habitual / general sense. "In the summer" — meaning summers in general, what you usually do — is om sommeren, with the season in its definite form (the -en / -eren ending). This om + definite pattern is distinctly Norwegian and has no clean English equivalent; English just says "in summer" for both the general and the specific. Use om when you mean "in summers generally": om vinteren går vi på ski — "in winter we go skiing (as a rule)."

A fuller treatment of i vs på in time expressions (including specific seasons like "this summer," which behaves differently) has its own page; what you have here is the everyday core that covers most situations.

Common Mistakes

Capitalizing days, months, or seasons. English capitalizes "Monday" and "January"; Norwegian does not. This is the number-one English-transfer spelling error.

Using 'på' for months (translating 'on/in' directly). Months take i, not på.

Using 'i' for habitual seasons. The general "in summer" is om sommeren, not "i sommer" (which means "this coming summer" — a different thing).

Misspelling the ø/å words. Lørdag, søndag, høst, vår all carry diacritics; plain o/a changes or breaks the word.

Key Takeaways

• Days (mandag…søndag), months (januar…desember) and seasons (vår, sommer, høst, vinter) are all lowercase — the top English-transfer error.
• The week starts on mandag; all of these words are masculine nouns.
• Conventional prepositions: på
  • day, i
    • month, om
      • season (with the season definite: om sommeren).
• Watch the diacritics: lørdag, søndag, høst, vår — and remember vår also means "our."