Well no you do not fly for 28 hours as that isn't realistic you do it in many hops.
For example me and tawm may be doing a flight tonight from Manchester to Heathrow to Paris back to Heathrow and back to Manchester but there is a thing called time acceleration but that just spoils the fun. Longest flight I've done was about 7 hours rounded up.
Tom have you heard of FSNavigator? It's like an fmc and you can use it with any aircraft.

