After the Breaking it took almost two hundred years but eventually nations did emerge.

In 209AB ( Toman Calendar adopted approx. 10 years earlier ) the Compact of the Ten Nations was formed.
Known as the Second Compact it was largely the work of Queen Mabriam of Aramaelle, reported to be Aes Sedai.

The Ten Nations

Nation	Ruler	City Transitions
Aelgar	King Remedan the Goldentongued	Mainelle -> Tanchico
Almoren	King Coerid Nosar	Al'cair'rahienallen-> Cairhien
Aramaelle	Queen Mabriam en Shareed	Mafal Dadaranell -> Fal Dara
Aridhol	Queen Doreille Torghin	Aridhol -> Shadar Logoth
Coremanda	King Ladoman	Braem -> New Braem Hai Caemlyn -> Caemlyn
Eharon	King Temanin	Barasha -> Ebou Dar Dorel Caromon -> Illian
Essenia	First Lord Cristol	Aren Mador -> Far Madding Tear
Jaramide	High Queen Egoridin	Deranbar -> Maradon Alorallen -> Bandar Eban
Manetheren	Queen Sorelle ay Marena	Shanaine -> Jehannah
Safer	King Eawynd	Iman -> Katar Miereallen -> Falme

The Compact lasted for roughly eight hundred years, and the people lived in relative peace and prosperity until 1000AB when the Trollocs came south.

Trolloc Wars

Trolloc Wars spanned approx. 350 years.
There were some few Trolloc archers.

The lack of Trolloc archers bothers me. It could be argued on the one hand that they don't have the discipline for co-ordinated archery in combat, but OTOH archery seems perfect for a Fade-linked Fist - especially when you consider that there would be almost no danger to the Fade in this instance.

The Compact was successful in that each nation rallied to support the war effort and the other nations but it was weakened by each nation's insistence on maintaining its own separate armed forces. The White Tower supplied Aes Sedai to assist the armies of the Compact against the Dreadlords, but even those Aes Sedai were under command of the Tower alone.

Military Organisation.

• At this time the military formed Banners, which consisted of roughly fifteen hundred horse, primarily archers, or three thousand infantry.
• As well as soldiers there were Banner's Musicians, who after battle served as stretcher bearers.
• Banners could be either heavy or light depending on their arms and armour.

• Banners grouped together into a legion which usually combined foot and horse, although it could be either alone.
• It was possible for an entire legion to be heavy or light, but usually they were mixed.
• A banner of artillery, (smaller in numbers than a banner of horse, though apparently no fixed number ) comprised catapults and huge crossbows that fired spears and was often part of the legion as well.

• Legions were grouped together into Grand Legions.
• An Army consisted of four Grand Legions one of which was normally designated as the reserve.
• These Armies were under the command of a general often a noble and were usually accompanied by a small complement of Aes Sedai.

• The Army always included a Supply Banner and a Logistics Corps, often numbering as many men as a Grand Legion itself.
• A Miners' Banner was also included - this banner's men were often assigned individually to various groups.
• The Signal Banner operated in a similar fashion.

The Banner and Legion structure disappeared during the latter part of the War of the Hundred Years.

Anti-Trolloc Tactics : After long harassing actions by cavalry, human infantry took up a defensive position in front of the wave, holding it long enough for mounted archers to move in from the sides and whittle the enemy down safely from a distance. Those Trollocs not destroyed in the pincer broke and ran. Both cavalry and infantry had to be fast, and the infantry had to have the courage to stand against an onslaught by monsters. If the force was too large for the infantry to hold, the human army would pull back to let it pass then hit it from the sides and rear.

Conclusion : Trolloc incursions managed to reach as far south as Tear and Illian.
In Manetheren, Elderne used the One Power to hunt down the victors, and supposedly sent balefire to consume the Dreadlords, Myrddraal, and Darkfriends where they stood.

In direct contravention of the well-established 'must be able to see exactly what you're doing' rule that normally applies to channeling.

After almost three hundred years of fighting the Trollocs were soundly defeated at the battle of Maighande.

Aftermath : Aelgar, Eharon, Essenia, Jaramide and Safer survived after a fashion, but within fifty years new nations were assembled.
However the White Tower survived, and even gained lands and influence.

Given that nations survived, and that the White Tower was fully intact, I can't see how it's possible for the dates to get mixed up to the extent that they require a new calendar, especially when you consider that three hundred years isn't that long for an AS, or indeed for an Ogier - and don't forget that the Ogier were out and about during the Trolloc Wars, not confined to the stedding as is the norm now.