Expressing dates or the passage of time in German sometimes parallels English, and sometimes doesn't. Let’s take a closer looks to get our dates straight.
The standard expression “on the [day] of [month]” is similar in form to English:
Am dreizehnten April zweitausendneunundzwanzig...
On the thirteenth of April, two thousand twenty-nine. ..
Caption 48, Unser Universum, Asteroiden: Gefahr aus dem All
The expression of passing time “from the [day] of [month] to the [day] of [month]" goes like this:
Vom achtzehnten Juni bis zum zwölften Juli...
From the eighteenth of June till the twelfth of July. ..
Instead of vom, the preposition ab can be used to express the start of an event:
Ab Juni wird der Riesenvogel dann in Linienbetrieb gehen.
From June, the giant bird will be starting route service.
Caption 49, Rund um den Flughafen: Der neue Airbus A-380
One German date-related expression that differs from English is "Wir haben gerade":
Wir haben gerade Oktober.
Just now, we have October.
Caption 5, Herbst: mit Eva
Yabla has translated this very literally in order to show the language parallels, but another way of translating Wir haben gerade Oktober could be: “It is now October.”
If you state the day of the week with the date, you use the form: Am Freitag, dem 21. Februar. Note the dative article dem used for the month. On the other hand, if you are writing a formal letter, you write the city name and the accusative article: Berlin, den 21. Februar. There has been a creeping tendency recently in German to express the year (in German) as in 2014, which is an Anglicism and considered poor style in formal German. Historically, German uses either just 2014 or im Jahr 2014, but not in 2014. Natives speakers of English learning German often get confused about this; luckily now you know better!