"The hours of the day."
Swedish, along with Spanish and Irish, is my 4th foreign language after English, Latin and French. Prepositions are best learned by constantly using them over and over in the right context and paying attention on how native speakers use them, when immersed in the language. Then they get a 'natural feel' to them, just like your initial tongue...
It is not related to the English language. Something important that everybody should know. European languages have their origin in Greek and partly in Latin. A few additions are the simply making the difference. In Greek, 24ωρο means a whole day. In Swedish månad means month. It is a unit of the year and it is monada. If you need more to make your Swedish learning easy, I am French oh Greek distant origin with excellent Greek, Latin, English, French and Italian.