Fredag aften? Det passer mig fint.

In Danish, time expressions like mandag morgen, fredag aften, i morgen, and næste uge often appear without a preposition.

So Fredag aften? simply means Friday evening? as a suggested time.

You can sometimes use a preposition in other structures, but in a short suggestion like this, Fredag aften? is the natural choice.

Examples:

• Mandag? = Monday?
• I aften? = Tonight?
• Fredag aften? = Friday evening?

Not really in a formal grammatical sense, but it is a very natural elliptical question in conversation.

It works like English:

• Friday evening?
• How about Friday evening?
• Friday night?

Danish often leaves out words when the meaning is obvious from the situation.

Here, passer means suits, works for, or is convenient for.

So Det passer mig fint means something like:

• That suits me fine
• That works well for me
• That’s fine with me

This is a very common Danish expression when talking about plans, times, or arrangements.

Because mig is the object form of jeg.

In Det passer mig fint, the verb passer takes mig as its object:

• jeg = I
• mig = me

So Danish works like English here:

• It suits me not
• It suits I

In this expression, det is a kind of formal or anticipatory subject. Danish often uses det in expressions where English might say that or just begin directly with the idea.

So:

• Det passer mig fint = That suits me fine / It works well for me

The det refers to the suggestion just mentioned: Fredag aften.

Fint here means fine, well, or perfectly okay.

It softens and completes the phrase:

• Det passer mig = That suits me
• Det passer mig fint = That suits me fine / That works great for me

In everyday speech, fint often gives a friendly, relaxed tone.

Yes, you could, and it would be understood.

But there is a small difference:

• Det passer mig fint = more specifically that time/plan suits me
• Det er fint for mig = more generally that is fine with me

When replying to a suggested time, Det passer mig fint is especially natural.

People would probably understand you, but Det passer mig fint is the more idiomatic phrasing.

Danish commonly puts the person directly after passer:

• Det passer mig fint
• Det passer ham ikke
• Passer det dig?

So for a learner, Det passer mig fint is the safest and most natural version to remember.

No.

• aften = evening
• nat = night

So fredag aften is Friday evening, not Friday night in the late-night sense.

That said, in natural English translation, Friday night? may sometimes sound more idiomatic depending on context, even though the Danish word is aften.

In Danish, days of the week are not normally capitalized.

So normally it would be:

• fredag aften

In your sentence, Fredag has a capital letter because it comes at the beginning of the sentence.

This is different from English, where Friday is always capitalized.

Very natural already. In speech, you might hear:

• Fredag aften? Det passer mig fint.
• Ja, fredag aften passer mig fint.
• Det lyder fint.
• Det kan jeg godt.

The original version sounds polite, natural, and conversational. It is exactly the kind of thing a Danish speaker would say when agreeing on a time.