The purpose of my method is to get the currentTime, and set it back for 20 minutes. For what I can see, my method is correct, but the output shows something else.
This
AddMinutes returns a new DateTime object so you need:
DateTime
DateTime currentTime = DateTime.Now; double minuts = -20; DateTime newTime = currentTime.AddMinutes(minuts); Console.WriteLine("Nuværende tid: "+newTime);