The timeline concept of the movie is quite segregated, there are various types of events taking place simultaneously yet usually independent from one another. Sometimes one character at the diner than at the home then somewhere else but you can't calculate the time between these events. Such movie making technique was once common, in fact it could be seen in some movies like "The Hollywood Knights", "Fast times at Ridgemont High", "American Graffiti", "Dazed and Confused". In short, if like these movies you will probably like "Diner" too. Have fun...
