The book To Kill a Mockingbird starts out during the summer of 1933. The reader is introduced to Dill, whose real name is Charles Baker Harris. Dill comes to Maycomb for the summers to live with his aunt, Miss Rachel Haverford. Dill is a summertime character through most of the novel. He arrives at the start of summer and leaves just before school starts. His arrival and departure signal the beginning and end of summer. In other words, Scout can finally have some fun because of the arrival of Dill. His presence in Maycomb can be representative of June, July, and August. The rest of the months he is absent. Painting a larger picture, the return of Dill signifies to the reader that an entire year has passed by. The reader is brought through a full year's time by the time Dill comes for the second summer. Later in the book, though, Dill runs away from his home and arrives back in Maycomb before the next summer.
In Lee's To Kill a Mockingbird, Dill only spends summers in Maycomb, Alabama. Therefore, he represents the beginning of summer when he arrives and the end of summer when he leaves. Scout looks forward to Dill and summer equally, and she always mentions when he comes and goes. For example, at the beginning of chapter 2 she says the following:
"Dill left us early in September, to return to Meridian. We saw him off on the five o'clock bus and I was miserable without him until it occurred to me that I would be starting to school in a week" (15).
The above passage marks Scout's first year of school when she is six-years-old. Dill shows up again for the second summer in chapter 4, which signifies the passage of one year. Scout describes waiting for summer and Dill as follows:
"Summer was on the way; Jem and I awaited it with impatience. Summer was our best season: it was sleeping on the back screened porch in cots, or trying to sleep in the treehouse . . . but most of all, summer was Dill" (34).
Chapter 6 revolves around Dill's last night in Maycomb during the second summer. This is when Jem sneaks into the Radleys' backyard. Dill leaves the next morning; and in chapter 7, Scout says, "The second grade was as bad as the first . . ." (57). This comment signifies that Dill has left and the second summer has ended.
Dill doesn't return until chapter 14; and even though he runs away from home on this occasion, this happens at the beginning of the third summer. The story ends on Halloween night after the third summer, and Dill has been back at school for over a month by this time. Therefore, the timeline for the novel spans about 2 and a half years of time.