German Time Expressions: When to Use Um, Am, and Im (and When to Skip the Preposition)
If you're learning German, almost every answer to Wann? (when?) starts with a short word: um, am, or im. They look similar, but they don't mean the same thing, and German speakers swap them constantly without thinking.
The rule is simpler than most learners expect. Clock times use one word. Days and dates use another. Months and seasons use a third. A small group of expressions use no preposition at all. Once you know which type of time you're talking about, the right preposition is automatic.
Try it first
Here's a quick five-round practice before the explanations. Each question shows a sentence with the time preposition missing. Pick the one you'd say. The feedback after each answer matters more than the score, so don't worry about getting everything right.
If some of those felt random, the next sections explain why each one is what it is.
The question word: Wann?
In German, Wann? means "when?". Every time expression in this post is an answer to that question. So when you read the rules below, picture yourself answering Wann kommst du? (when are you coming?) or Wann hast du Geburtstag? (when is your birthday?).
The answer almost always has this shape:
[preposition] + [time word]
Your job is picking the right preposition for the kind of time word that comes next. There are only three main ones to learn.
The three workhorse prepositions
These three cover most everyday German time expressions:
- um for exact clock times: um 3 Uhr (at 3 o'clock)
- am for days, dates, and parts of the day: am Montag (on Monday), am Morgen (in the morning)
- im for months, seasons, and centuries: im Juli (in July), im Frühling (in spring)
If you remember nothing else, remember those three. They handle most of what you'll ever say.
The reason am and im exist in the first place is that they're contractions. Am is short for an dem, and im is short for in dem. Both are the Dativ forms of an and in. You don't need to think about this when you speak. Germans almost never expand the contractions out loud.
Um: exact clock times
Use um whenever you point to a specific time on the clock.
- Ich komme um 3 Uhr. (I am coming at 3 o'clock.)
- Das Meeting beginnt um halb 7. (The meeting starts at half past six.)
- Der Film startet um Viertel vor 5. (The movie starts at quarter to five.)
- Sie kommt um Mitternacht nach Hause. (She comes home at midnight.)
The pattern is um + Uhrzeit. It also works for the 24-hour clock: um 16 Uhr (at 4 p.m.).
One useful detail: when you combine a clock time with a part of the day, you still use um. The clock time wins.
- Der Zug fährt um fünf Uhr morgens. (The train leaves at 5 in the morning.)
- Ich gehe um ein Uhr nachts ins Bett. (I go to bed at 1 at night.)
So um is the preposition for any sentence where you can put a number on it.
Am: days, dates, and parts of the day
Am is the busy one. It covers weekdays, parts of the day, and specific calendar dates.
For weekdays:
- Ich arbeite am Montag. (I work on Monday.)
- Wir treffen uns am Samstag. (We meet on Saturday.)
For parts of the day (except Nacht, which we'll cover in a moment):
- Ich lerne am Abend Deutsch. (I study German in the evening.)
- Sie joggt am Morgen. (She jogs in the morning.)
And for specific calendar dates:
- Ich habe am 23. August Geburtstag. (My birthday is on August 23rd.)
- Wir feiern am ersten Mai. (We celebrate on the first of May.)
You can also combine a weekday with a part of the day, and it still takes am:
- Wir treffen uns am Sonntagnachmittag. (We meet on Sunday afternoon.)
- Sie hat am Freitagabend frei. (She has Friday evening off.)
Think of am as the calendar preposition. If you're pointing at a square on a calendar (a day, a date) or a chunk of the day other than the middle of the night, you use am.
The Nacht exception
There is one annoying exception to the parts-of-the-day rule. Nacht (night) doesn't take am. It takes in der.
- Ich schlafe in der Nacht. (I sleep at night.)
Yes, it's just Nacht that breaks the pattern. You say am Morgen, am Mittag, am Nachmittag, am Abend, but in der Nacht. There's no logical reason, you just memorize it.
The good news is that in der Nacht is a fixed phrase. You don't need to think about why in der is there (it's the Dativ form of in with a feminine noun). Treat it like a chunk and move on.
Im: months, seasons, and centuries
The third workhorse is im. It covers anything bigger than a day.
For months:
- Ich fahre im Juli nach Deutschland. (I am going to Germany in July.)
- Im März wird es wärmer. (In March it gets warmer.)
For seasons:
- Im Frühling ist das Wetter schön. (In spring the weather is nice.)
- Im Winter fahre ich Ski. (In winter I go skiing.)
For centuries, which are less common in everyday conversation:
- Im 19. Jahrhundert. (In the 19th century.)
- Im 21. Jahrhundert. (In the 21st century.)
The rule is the same in all three cases. If the time word is a big block of time that contains many days, you use im.
When you skip the preposition entirely
This is the part most textbooks underexplain. A handful of German time expressions don't take any preposition at all. If you put one in, it sounds wrong to a native speaker.
Years stand alone:
- Ich bin 1985 geboren. (I was born in 1985.)
- Wir haben 2017 geheiratet. (We got married in 2017.)
Notice how English uses "in" before the year. German doesn't. Just the number, nothing in front. (You can say im Jahr 1985, but the bare year is more common.)
Time adverbs ending in -s also stand alone:
- Ich trinke morgens Kaffee. (I drink coffee in the mornings.)
- Abends lese ich. (In the evenings I read.)
These look like am Morgen and am Abend, but they're different words. Morgens and abends are adverbs that already mean "in the mornings" or "in the evenings" by themselves. Putting am in front would be like saying "in in the mornings" in English.
Akkusativ time phrases are the third group with no preposition:
- Ich fahre diesen Winter Ski. (I am skiing this winter.)
- Ich habe nächste Woche Zeit. (I have time next week.)
- Ich war letztes Wochenende zu Hause. (I was at home last weekend.)
These phrases use the Akkusativ case (diesen, nächste, letztes) instead of a preposition. The case ending does the work that the preposition would do. You memorize the pattern: diesen / nächste / letztes plus the time word, no preposition.
The quick summary
If you only keep one thing from this post, keep this table. It covers almost every A1 and A2 time expression you'll meet.
| Type of time | Preposition | Example |
|---|---|---|
| Exact clock time | um | um 3 Uhr |
| Part of the day | am | am Morgen, am Abend |
| Night (exception) | in der | in der Nacht |
| Day of the week | am | am Montag |
| Specific date | am | am 23. August |
| Month | im | im Juli |
| Season | im | im Frühling |
| Century | im | im 21. Jahrhundert |
| Year | (none) | 1985 |
| Adverb (morgens etc) | (none) | morgens, abends, nachts |
| Akkusativ phrase | (none) | nächste Woche |
The pattern, in one sentence: clock takes um, days and dates take am, months and seasons take im, Nacht is the odd one (in der Nacht), and years, adverbs, and Akkusativ phrases use no preposition.
Common mistakes English speakers make
Saying "am Nacht"
You'd expect am Nacht by analogy with am Morgen and am Abend. It's wrong. Always in der Nacht.
Putting "im" in front of a year
In English you say "in 1985". In German you just say 1985. Im 1985 is incorrect. If you really want a preposition there, you have to say im Jahr 1985, but most Germans just use the bare year.
Mixing up "am Morgen" and "morgens"
Am Morgen means "in the morning" (today, a specific morning). Morgens means "in the mornings" (in general, every morning). They sound similar but they're not interchangeable, and you can't put am in front of morgens.
Also watch out: morgen without the -s means "tomorrow". Morgens with the -s means "in the mornings". One letter, two completely different meanings.
Treating dates like English
In English we say "on August 23rd" and "in March". German uses am for the first one and im for the second one, never the other way around. The size of the time chunk decides the preposition. A specific day uses am. A whole month uses im.
What actually makes this stick
You can read this post twice and still hesitate when someone asks you Wann hast du Zeit? The only thing that fixes the hesitation is repetition with feedback.
The short game at the top of this post is a quick sample. The full German Time Expressions Game uses the same format with many more sentences and longer rounds, so you can drill until um, am, and im feel automatic.
Go play a round. Five minutes a day for a week is usually enough to stop second-guessing.