I was wondering when the accusative is used with dates, and if so, do the ordinal numbers decline like adjectives?
Montag den ersten Januar (acc)
... why not Montag der erste Januar? (nom)
German Language Stack Exchange is a bilingual question and answer site for speakers of all levels who want to share and increase their knowledge of the German language. It's 100% free, no registration required.Sign up to join this community
First, observe that in weekday–date constructions, the date is an apposition to the weekday. And the general rule says that appositions are declined in the same way as the phrase it refers to. Therefore, the case depends on what you want to say:
- Heute ist Montag, der erste Januar. (nominative)
- Wir halten Montag, den ersten Januar, im Kalender fest. (accusative)
- a. Wir treffen uns am Montag, dem ersten Januar. (dative)
However, for weekday–date constructions there is an exception to the general rule: If the phrase is in dative case, the apposing date can also be put in accusative case. Therefore, you can also say
- b. Wir treffen uns am Montag, den ersten Januar. (weekday in dative; date in accusative)
So, both 3. a. and 3. b. are correct, even though some people consider 3. b. as bad style.
Moreover, the numerals are, in fact, adjectives and must be declined accordingly.
This is because the accusative case is not only used for direct objects, but also for adverbials of time. If you use a weekday (or date) in a sentence, it is usually in the accusative (unless you use a prepositional phrase such as «am Montag»):
ich sehe dich Montag wieder – ‘I see you again Monday’
Now you obviously cannot see that this is an accusative. It only shows when you expand the phrase, e.g. with an article and an attribute:
ich sehe dich den ganzen Montag wieder – ‘I see you again all Monday’ (literally: ‘the entire Monday’)
Or with an apposition, which takes the same case as the phrase it is being added to:
ich sehe dich Montag, den ersten Januar, wieder – ‘I see you again Monday the first of January’
When a weekday or date is used in isolation, it is usually thought of like an adverbial of time and therefore takes the accusative. This is because dates usually answer to the question of when:
wann sehe ich dich wieder? – Montag, den ersten Januar
‘when do I see you again? – Monday the first of January’
Sidenote: It may seem strange that the accusative can not only express direct objects, but also adverbials of time. The common ground to both usages may be the notion of a goal.