1. in town.
2. Miss Emily asks the druggist for poison.
3. The townspeople discover the bridal sweet.

Obviously, this is not in chronological order, because Emily is introduced as dead, and then the collective narrators flash back to her earlier life.  However, Homer Baron's event are in a kind of chronology: he is first introduced, then said to have disappeared, and then, at the end, we find his bones in the bed.

If Faulkner would have put Miss Emily's events in chronogical order, it would have culminated in her death, not his, thereby undercutting the horrifying discovery that the townspeople make (Miss Emily lying in bed with Homer Baron's corpse).  It should have been no mystery that Emily died, or Homer for that matter.  It should have been no mystery that Emily poisoned Homer.  The mystery comes when we discover her necrophelia. 

Key to understanding Faulkner's framing of the story with the old chivalric code of the ghostly Old South's past with Part I and Part V, is his creation of a gothic horror with the gruesome details of a past perverted by noblesse oblige and the lost moments of youth tainted with age and grotesquely reclaimed in the present. Indeed, Faulkner has arranged his narrative in the order of one of his statements:

Thus she passed from generation to generation--dear, inescapable, impervious, tranquil, and perverse.

Putting the story's "ending" at the beginning is a method of creating tension and suspense in fiction. This method is often used in film as well. 

When the audience has a specific event, episode, or idea to anticipate, the story becomes naturally imbued with some amount of tension. The question of the story presents to the reader becomes a "how" question (How does the predicted outcome come to pass?), which is a twist on the more-or-less standard "what" question in narrative (What happens in the story?). 

Faulkner uses this method well and subtly undermines the certainty with which he begins the story. At the opening, a simple and definite event is predicted. By the end, that same event is no longer so simple or definite because we have come to learn so much about the character.

One of the things that makes "A Rose for Emily" such a classic short story is Faulkner's use if a fractured time line.  The story is written in parts; each part gives certain details about the mysterious Miss Emily Grierson.  

Faulkner was having fun with the reader.  He knew it would a little frustrating to not have the story written in an ordinary order.  If the story were told in chronological order, the story would not be in the realm of a masterpiece in American literature. 

If the reader begins at the start of the story, it is the funeral of Emily.  The story ends after her funeral with the citizens coming into her house to find out about what has been up in the upstairs bedroom.  Now what happens in between has to be put in order. 

Chronologically, in the first section, you are given a date 1894 when Colonel Sartoris paid Emily's taxes. 

In section two, the smell that came from Emily's house was thirty years before the new councilmen came to get Emily to pay her taxes.  This was two years after her father's death. It was also a short time after Homer Barron disappeared.  

She was about 30 when her father died.  

In section three, about a year later after her father died, Homer Barron comes to town. Emily would have been about 31 years old. 

This is the time that she went riding with Homer.  Her cousins came. She bought arsenic and the men's clothing. 

Section four

Shortly, after this, Homer disappeared after being seen going in the backdoor of Emily's house.We learn that Emily was 74 years old when she died. 

From this point, the reader should be able to see how to put the entire story in chronological order.   It should be easy because there are not that many new events in the last section other than finding Homer's skeleton in bed with Emily's gray hair on the pillow next to him. 

What a fun story!

One of the reasons that the story is not told in order is that the plot is not as important as the theme.  Like the characters, we are left to experience the story in pieces until we get the whole thing, and realize what Emily's story has to tell us about love, pride, and tradition.

The short story "A Rose for Emily" by William Faulkner tells of an eccentric, reclusive woman in a Southern town who ends up murdering her lover and living with his corpse for many years. It is a character study as well as a study of the small-town Southern mentality during the years in which the story takes place.

This story is not narrated in chronological order for several reasons. First of all, beginning the story at Emily's funeral gives the tale an atmosphere of reminiscence, of looking back over the life of a woman who the townspeople never really understand. It also creates an illusion that Emily is a person of significance and importance in the town. The story is told from the viewpoint of one of the people in the town, and it is narrated in an erratic, disconnected collection of impressions because that is how outsiders observed Emily: in brief flashes between long periods of isolation.

Additionally, the way the story is told builds sympathy for the main character, Emily, so that when the shocking truth about her lover is revealed in the last paragraphs, the reader sees her as a tragic victim of her circumstances rather than merely a cold-blooded murderer.

It is important to realise that flashbacks and disrupted narration are key tools of gothic writers, who use such narrative techniques as part of the overall unsettling feeling they wish to produce in their readers. Having a non-chronological narration forces the reader to jump back and forth between different time periods and is deliberately unsettling as we have to focus on which time period we are focussing on, and also we need to be especially aware of how foreshadowing is used to show how what is revealed to us in the future or the past relates to the present.

In this short story in particular, jumping back and forth highlights and emphasises the way that values in the Old South have changed, which is of course, one of the key themes of this story.

In order to best answer your question, let's switch and suppose that William Faulkner had written "A Rose for Emily" in order. Although the plot would have followed the same events, but merely in a straight sequence, an important part of the narrator's voice would have been lost in the process. In a typical third person narrative, we know what happens but we do not get the insight that would be obtained from a narrator who is taking the perspective of a first person who has seen and heard what went on in Jefferson. This is what we can appreciate in "A Rose for Emily".

Faulkner wanted to tell his story from the perspective of the townsfolk: Different voices who have seen different things at different times, all coming together into one narrative. It is exactly the manner in which you get information from neighbors when a huge event, or even a tragedy, happens in your vicinity: One person witnesses this, another witnesses that, and all the sights, sounds, and stamps that each person brings to the story are put together to somehow foreshadow what may happen next.

If you notice, the entire time that the narrator speaks, he or she uses the pronoun "We". These combined voices have witnessed Emily since her youth under the willful protection of her father, then as a grieving daughter, then as a spinster, and then as the rebellious older lady to defies all conventions and goes about with a Yankee of dubious origins. Suddenly, they see her no more, and all wonder what happens to Emily and to Homer.

Hence, all of these small but powerful details would have been hard to infuse in a third person detached narrative that lacks the spice and flavor of the "neighborhood gossip" that permeate the narrative of "A Rose for Emily".

In Requiem for a Nun, Faulkner writes, "The past is never dead. It's not even past." Much of his work, including this short story, offers a meditation on the past, and the narrative structure reflects that. As a Modernist, Faulkner also tends in his work to explore non-linear time.

In "A Rose for Emily," it is somewhat misleading to think of this story as a story about Emily Grierson. It is much more about the act of narration and the implied audience of the story. The narrator is unfolding this horrific story about a town's legendary character, and the reader stands in for that auditor. A reader response critique can explore that more fully, but as is the case in any dramatic monologue, the implied experience of the teller and the hearer adds a depth. This is especially true as the story is past tense and the "unspeakable" ending has been awaiting discovery all along.

Without the framing device in which we enter the past from the present time, the disturbing brilliance of the story would be lost. Like the South who knew its own decay but denied it, Emily and the town also live amidst its rotten past. The story brings that vividly to the reader, who must reconstruct the story's time line but then realizes that the grim truth of Emily's life should have been obvious to anyone not actively seeking to deny it.

The following order of the story maps out Emily's life chronologically.

1. Emily is a young girl/woman with a father who parades her around town and denies her opportunity to marry.

2. Her father dies and she is unwilling to acknowledge the fact or deal with the dead body for three days.

3. Emily has an independent maidenhood, indulged by the elders of the city who remember an earlier grandeur. This period includes a brief stint giving china painting lessons and a brief romantic attachment to Homer Barron, which seemingly leads to a marriage proposal (hence the silver toiletry set).

4. The town and her cousins express scandalized horror at the thought that Emily might marry a Northerner; Homer leaves.

5. Homer returns.

6. Emily buys rat poison despite being unwilling to offer a good reason for her need to do so.

7. There is a terrible smell that the town attempts to deal with.

8. Emily dies.

9. The town discovers that Emily had slept in the same bed on which the corpse of Homer was lying.

Flashing back in time is used by authors to produce a desired effect. In this story, not telling the story in the time order that events happened is much like how our human memory works.Throughout the story, the narrator goes back and forth through the events in the life of Emily and the town. One memory prompts the narrator to remember a different memory. I'm sure we all know someone who tells a story this way. We don't always remember everything at the same time, but as we recall one event in our past, it reminds us of something that triggers a memory of another part of the story. Our memory of what happened is sometimes haphazard.

Because Faulkner wants us to understand the full culpability of the town in Emily's isolation, loneliness, and eventual death. Her story and the town's responsiblity is best realized in retrospect.

The story begins with her funeral; the entire town attends, making us think that this is a caring community. But soon recounted events tell the real tale. We learn of Emily's life before her father died, of her illness, and of the one beau she manages to acquire. Then we learn of his abrupt departure and of the onset of her isolation from the town. All the events culminate in the discovery of the body of her former lover and the indentation of her head upon the pillow next to the corpse, a stray gray hair clinging to the fabric.