Date and time notation in Finland

In Finland, the usual way of writing dates in normal text is with the months spelled out. The format varies according to the language used. In Finnish, a full stop (full point, dot or period) is placed after the day to indicate an ordinal: 31. toukokuuta 2002; furthermore, the month is in the partitive case, always marked by -ta. The month can also be written first, now in genitive case (the day and the abbreviated word päivä, 'day', are in essive case as above): toukokuun 31. pnä 2002. In Swedish, the full stop is not used and the month is in nominative (without inflection): den 31 maj 2002.

The date can be preceded by the weekday (also lower case), in Finnish in essive case: perjantaina 31. toukokuuta 2002, fredagen den 31 maj 2002. The Finnish language has month names differing from most other languages; three letter abbreviations are not used in Finnish, and the months are not capitalised in either language (they are not considered proper names). In spoken Finnish in a context where it is clear people may say the short form of the month e.g. loka for lokakuu 'October', but never in formal writing as several months also can be times of the year e.g. joulukuu 'December' whereas joulu is yule or Christmastide; kesäkuu 'June' is similar to kesä 'summer'.

In the Sami languages (Inari Sámi, Northern Sámi and Skolt Sámi) the date can be given with the month first, but then spelt out in essive case: vyesimaanu 31. p. 2002, bearjadat, miessemannu 31. b. 2002, vue'ssmaan 31. p. 2002. The all-numeric form for dates is in the order day–month–year, using a full stop as the separator – for example: 31.5.2002 or 31.5.02. Years can be written with two or four digits, after the turn of the millennium usually with four, and numbers may be written with or without leading zero. The numeric form is often used in lists, letterheads, etc. A form with a stroke is also common in Swedish, especially in handwritten text: 31/5 2002 or 31/5 -02. The weekday may be prepended: fredag 31/5 -02.

The ISO 8601 notation (2002-05-31) is not used in normal text in Finland, but it is understood and used in some other contexts (mostly machine-generated).

Numbering of weeks is used in Finland, and is simply expressed as in (viikko) 28; (vecka) 28 ('(week) 28') in both writing (abbreviated vk in Finnish and v. in Swedish ) and speech, as well as on labels and in computer notation. The week begins with a Monday and week 1 is the week containing the year's first Thursday.

Time in Finland often uses the 12-hour clock in the spoken language and idiomatic expressions. 24-hour notation is used in writing, with a full point as the standardised and recommended separator (e.g. 15.07 or 8.27). However, a colon is almost exclusively used instead of a full point in computing environments, especially in Sámi languages. The conventions are the same for Finnish and Swedish.