Ordinal Numbers for the Late Month
When counting past the 20th, Finnish uses compound ordinal numbers. Just like in English, you combine the ordinals for both parts. For example, "twenty-first" is literally "twentieth-first" (kahdeskymmenes + ensimmäinen).
When you are simply stating what the date is, the ordinal number stays in the basic nominative case.
| The twenty-third of March is a bright day. | Kahdeskymmeneskolmas maaliskuuta on valoisa päivä. |
Saying "On the [Date]"
To say that something happens on a specific date, the ordinal number takes the essive case (-na/-nä).
The rule for compound numbers is that every part of the number must be inflected. Since "twenty-first" is built from three components (2nd + 10th + 1st), all three take the essive case to say "on the twenty-first".
| Nominative part | Essive part | Meaning |
|---|---|---|
| kahdes | kahdentena | 2nd (as in 20th) |
| kolmas | kolmantena | 3rd (as in 30th) |
| kymmenes | kymmenentenä | 10th |
| ensimmäinen | ensimmäisenä | 1st |
| toinen | toisena | 2nd |
Chained together, "on the twenty-first" becomes kahdentenakymmenentenäensimmäisenä. It looks intimidating, but is highly logical once broken down!
| I will pay the bill on the twenty-first of January. | Maksan laskun kahdentenakymmenentenäensimmäisenä tammikuuta. |
| The project ends on the twenty-second of November. | Projekti loppuu kahdentenakymmenentenätoisena marraskuuta. |
Late-Month Deadlines
The end of the month is often when bills are due and projects end. A very useful noun for these situations is eräpäivä (due date).
| due date | eräpäivä |
| Is the due date on the twenty-seventh or on the twenty-eighth? | Onko eräpäivä kahdentenakymmenentenäseitsemäntenä vai kahdentenakymmenentenäkahdeksantena? |
Notice how the sentence below contrasts the current date (nominative) with a scheduled event (essive).
| Today is the twenty-first, and the meeting is on the twenty-fifth. | Tänään on kahdeskymmenesensimmäinen, ja tapaaminen on kahdentenakymmenentenäviidentenä. |
This exact same pattern works for the 30th and 31st.
| The meeting is on the thirtieth of January. | Kokous on kolmantenakymmenentenä tammikuuta. |
| The summer ends on the thirty-first of August. | Kesä loppuu kolmantenakymmenentenäensimmäisenä elokuuta. |