It's that time

chronology--an arrangement of events in time, beginning with the earliest; a sequence of activities set forth at the time of occurrence; tracking a person, place, or process by its age and subsequent growth.

Chronology is to time as alphabetizing is to the alphabet, leading to some urban mythology among writers that biography and story must be set before the reader in time sequence, beginning with early, then working its way toward the present. Perhaps because they have been bored by strict chronology, readers have come to expect a severe stirring of the pot. Abraham Lincoln may well have been born in a log cabin in Hodgenville, KY in 1809, but most of the multitude of his biographies begin elsewhere, say as a young lawyer or congressman or even as POTUS. Novels often begin in medias res (see), working their way forward and backward at the hand of dramatic whimsy.

It is probably a good idea to know when and where characters were born so that a plausible background can be constructed for them, but the entire subject of chronology raises the better issue of the information a writer needs to know about a character as opposed to the demonstrable and implicit facts the reader knows and deduces. Entire mythologies have been created around such iconic characters as Sherlock Holmes and Sam Spade, but the original venues in which these characters appeared--dramatic narratives--do not rely on the mythology, they depend on the story.

Begin with a character's birth or some other significant rite of passage, if you must, but do not expect the reader to be as interested as you are, perhaps because the reader has not yet seen the character under stress or in thrall to some agenda, but equally perhaps because the mere fact of a birth, bar/bat mitzvah, christening, graduation is not of itself dramatic. The character George Amberson Minafer illustrates this point.

George is a principal character, you might even say a spoiler, in Booth Tarkington's novel, The Magnificent Ambersons. Named after his maternal grandfather, thus his first and middle name,

"At the age of nine, George Amberson Minafer, the Major's one
grandchild, was a princely terror, dreaded not only in [the]Amberson
[mansion] but in many other quarters through which he galloped on his
white pony. "By golly, I guess you think you own this town!" an
embittered laborer complained, one day, as Georgie rode the pony
straight through a pile of sand the man was sieving. "I will when I
grow up," the undisturbed child replied. "I guess my grandpa owns it
now, you bet!" And the baffled workman, having no means to controvert
what seemed a mere exaggeration of the facts could only mutter "Oh,
pull down your vest!"

"Don't haf to! Doctor says it ain't healthy!" the boy returned
promptly. "But I'll tell you what I'll do: I'll pull down my vest if
you'll wipe off your chin!"

That is George's introduction to us, from which point we move well back in time to the point where George's mother was engaged to a man much other than the one who became George's father.

A chronology is most useful for the writer when the work at hand involves the activities of a number of front-rank characters, some of whom may or may not know one another. In such cases, it is a useful guide for planning the order of scenes and, thus, the possibility of a particular character being able to appear in two successive scenes. Chronologies often provide alibis for suspects in mystery novels and, indeed, for stories in which sexual jealousy is a motivating factor.