be able to create a story timeline
To be able to create a graphic timeline of different storylines. A graphic timeline where I can create different color coded timeline for the main plot, each subplot, birth of character, death of a character, how many years past since this event etc... keep track of continuity.
Miguel Moreno commented
This. It's essential, but I would suggest to save time in developing new timeline features and instead provide integration & sync capabilities with existing timeline software, like Aeon Timeline, which the above quite well.