Use på with a day (på mandag), i with a month (i maj), and klokken with a clock time (klokken otte). Days and months are written in lower case.
Examples
- På onsdag har jeg undervisning.
- On Wednesday I have a class.
- I april tager jeg til Wien.
- In April I'm going to Vienna.
- Vi mødes klokken otte.
- We're meeting at eight o'clock.
The mistake to avoid
Klokken, not "på", introduces a time: klokken otte.
Where this fits in
Numbers, days, time, Danish A1: Count, talk about days and months, give the time, and handle numbers in real situations.