Starting date (associating to a standard system of chronology)
... Miles is about the 29th or 30th Century.
(LMB in Mailing List Plot FAQ)
- Today is November 2, 97, Earth Common Era.
("Borders of Infinity")

Strengthening of the Emperor rule on Barrayar.
The Imperium is like a very large and disjointed symphony, composed by a commitee. Over a three-hundred year period.
("Mirror Dance")

Time of Dorca's grand-uncle
Yes, but this is the cellar of the old old stables. Not Dorca's, but Dorca's great-uncle's. He kept over three hundred horses. They burned down in a spectacular fire about two hundred years ago...
("Barrayar")

Ten-Years' War
...he went out with a friend to see the pole-barge regatta on the river this morning. They have it every year; it commemorates the relief of the city by Vlad Vorbarra's forces during the Ten-Years' War.
("A Civil Campaign")

Vlad Vorbarra's marriage
Most other emperors had been safely married for years before they landed on the throne. Prior to Ezar one had to go back almost two hundred years, to the marriage of Vlad Vorbarra le Savante and Lady Vorlightly, in the most gaudily archaic period of the Time of Isolation.
("A Civil Campaign")

The metropolitain Vorkosigan House is built up.
It was the pre-electric Time-of-Isolation design that gave it such an air of fabulous age, Mark decided. The arcitecture he'd seen like it in London all dated back well over a millennium, though this pile was only a hundred and fifty standart years old. Vorkosigan House.
("Mirror Dance")
Vorkosigan House is about two hundred years old, now. It was built by my great-great-great grandfather, the seventh Count, in a moment of historically unusual family prosperity ended by, among other things, the building of Vorkosigan House... It replaced some decaying clan fortress down in the old Caravanserai area, and not before time, I gather.
("A Civil Campaign")

Regency
We haven't had a Regent in a hundred and twenty years, God knows what protocol they'll dig out and dust off.
("Barrayar")

Time of Isolation ends
It's only been eighty years since Barrayar made contact with the wider galactic civilisation again.
("Barrayar")
This station had been built nearly a century ago, when fresh explorations of the wormhole had yielded up the rediscovery of Barrayar.
("Komarr")

Xav Vorbarra on Beta Colony
My maternal grandfather was Prince Xav Vorbarra, the diplomat. He held the post of ambassador to Beta Colony for a time, in his youth, before the First Cetagandan War. I believe my grandmother was in your Bureau for Interstellar Trade.
("Shards of Honor")

Ceta's invasion begins
... There were about 15-20 years between the end of the Time of Isolation and the beginning of the Cetagandan invasion, by the way.
(LMB in Mailing List Plot FAQ)

Piotr's birthdate
The man was seventy-two standard years old, middle-aged for a galactic, old for harsh Barrayar... His father, Count Piotr, had lived twenty years more than that, a whole other lifetime.
("Mirror Dance")

Guerillia war against Cetagandians
... we were fighting the Cetagandans up in the Dendarii Mountains back behind Vorkosigan Surleau... I wasn't much older than you, then.
("The Warrior Apprentice")

Piotr promoted to General rank
Piotr had acquired his present rank at the age of twenty-two, fighting the Cetagandans in the fierce guerrilla war ... Rank was all then-emperor Dorca Vorbarra could give him at the time; more tangible assets such as reinforcements, supplies, and pay were out of the question in that desperate hour.
("Barrayar")

Aral's birthdate.
It wasn't just technology we lost, in the Time of Isolation. That we put back on again quickly, like a borrowed coat. But underneath it ... we're still pretty damned naked in places. In forty-four years, I've only begun to see how naked.
("Barrayar")

Ezar's birthdate. When Civil War begins and ends.
Date of Aral's commission
"How long have you served me, Aral?" asked the Emperor.
"Since my commission, twenty-six years. Or do you mean body and blood?"
"Body and blood. I always counted it from the day old Yuri's death squad slew your mother and uncle... How old were you?"
"Eleven, sir."
"Eleven. I was just the age you are now. Strange. So body and blood you have served me-damn, you know this thing is starting to affect my brain, now . . ."
"Thirty-three years, sir."...
The old man cleared his throat again. "I always meant to ask what you and old Yuri said to each other, that day two years later when we finally butchered him in that old castle."
("Shards of Honor")

Olivia Vorbarra-Vorkosigan and her older son die
Aral's mother's grave dated exactly to the start of Yuri's War. A space was reserved beside her for Piotr, and had been for thirty-three years. She waited patiently for her husband.
("Barrayar")
Intellectually, he'd known Aral Vorkosigan was the old General Count Piotr Vorkosigan's younger son, but that lost older brother had been dead for sixty years.
("Mirror Dance")

Ezar's marriage
The most recent wedding of a ruling emperor had been the scrambling mid-war union of Gregor's grandfather Emperor Ezar to the sister of the soon-to-be-late Mad Emperor Yuri...
("A Civil Campaign")

Cordelia's birthdate
... Old folks, too, of thirty-three and forty plus.
("Shards of Honor")

Infanticide becames a criminal offence.
Infanticide for obvious birth defects is still going on secretly in the back country, do you know, despite its being outlawed for fur decades?
("Brothers in Arms")

Aral's first marriage begins... and ends
He was married, at twenty, to a girl of high rank of eighteen.
("Shards of Honor")
And me -- me, of all men, to have to make that decision! Who should have been publicly executed twenty-two years ago for the self-same crime!
("Barrayar")

Aral breaks off with Ges Vorrutyer
The more I look back on Vorrutyer, the more he seems a tragic figure. Still obsessed with a love affair that was over eighteen years ago.
("Barrayar")

Karian mutiny
Soltoxin. It's been fifteen, sixteen years since I last smelled that stink, but you never forget it. It's a poison gas...
I was there, at the destruction of the Karian mutiny. Just about your age, I think, or a little younger. The smell brought it all back, just now.
("Barrayar")

Cordelia joins the Betan AstroSurvey
- Astronomical Survey? I thought your mother served in the Betan Expeditionary Force, in the Escobar War.
- Before the war, she had an eleven-year career in their Survey.
("Komarr")

Revocation of the "serfdom" - an ordinary subjects' lifetime liege oath
Among our father's early reforms, when he was Regent, was that he managed to impose uniform simplified rules for ordinary subjects who wanted to change Districts, and switch their oaths to their new District Count... Effectively, the new law gave every Imperial subject the right to vote local governement with their feet. Our parents drank champagne with dinner the night the vote slipped through, and Mother grinned for days. I must have been about six, because we were living here by then, I remember.
("A Civil Campaign")

Aral's Regency ends
My father gave away 275,000 marks the day before he left the Regency, just so he would have the exact financial balance as the day he took it up sixteen years earlier.
("The Warrior Apprentice")

Imperial Service opened for Komarrans
So, all right, the route to the top of dear old caste-consious, army-mad Barrayar was and always has been throught the Imperial Military Service. It was opened to Komarrans for the first time just eight years ago.
("Brothers in Arms")

The Barrayarian Imperial Service regulations is modernized
- ... I'll update regs as I go along.
- Your father and the General Staff did that fifteen years ago. It took them two years.
("The Warrior Apprentice")