Time distribution in a story is completely arbitrary. Some stories happen within hours or minutes. Others happen over days, months, years, or millennia. The "evenness" of the time flow is purely dependent upon the flow the problem solving takes in the story. Time elapsed within the story (Plot) is different than the progression of events as presented to your audience (Storyweaving). Audiences tend to expect things to flow relatively evenly -- at least in the way it is presented to them (Storyweaving). With that said, an author may choose to play to the audience's expectations or against them without changing the overall meaning embedded within the story.