Have you ever read a book that you had to look back several pages/chapters to figure out what day/month it is in the story? Did two weeks seems to pass, only to have the author imply two months have gone by? This is where the importance of Timelines comes in.
As writers, we know the setting, the time frame, and all the backstory--but the reader doesn't have that benefit, so we have to create a clear order of events to avoid confusion. Sounds like I'm promoting plotting, huh? Not exactly.
For Plotters--You've made storyboards, outlines, and maybe even a timeline or two for your stories. You've also learned not to info dump (hopefully!), which can happen when you know everything about your characters and plot before you begin writing. However, have you gone too far the other direction to avoid it? Do you have the right balance of information and events to allow your reader to see the sequencing and comprehend how much time has passed?
For Plantsers--Your characters tend to lead the story and often take you on surprising side-trips. So, how do you make sure your time frame is clear? Here's the method I use: I note when the story starts (May 15th). As I write, I jot down chapter numbers and when those scenes occur (May 16th, May 18th, May 21st, etc.), along a very brief description of what happened (first meeting of hero/heroine, heroine discovers hero has children, etc.). This keeps me focused on a chronological order of events happening between each of the major plot points I already know.
For Pantsers--You can use a similar approach to my Plantser method. Keep a record of dates/times and events/scenes as you write to track the story's progress. If the plot requires adjustments in earlier chapters, you then know where to find each particular day/moment in relation to the rest of the manuscript.
Whether you choose to make a detailed calendar or jot notes on index cards or paper, knowing the order of your story can help eliminate reader confusion in your final product. A good critique partner or beta reader can be invaluable for catching glitches as well.
In addition to providing a clear chain of events, your timeline can also help direct your synopsis.
Hmmm...Should I tackle that dreaded topic next week???
Romance...With A Kick!