Here I will try to make a semi-functional timeline with notable events.
How does the world keep its dates?
A universally accepted method of date keeping was decided upon by the convention of maesters. Now, how does the date work?
First write A.S(after separation or when Asariel and Luciel sealed Asarius away from the other continents) then the amounts of years since the last calamity and then the number of calamities or life-changing disasters that were deemed acceptable to change the calendar. This is a possible decision of discussion point during their quinquennial meetings.
For example: the 100th year of the third calamity would be written as followed:
A.S. the 100th 3.A.C.
Or for example the 72 year during the fourth calamity.
A.S. the 72 4.A.C.
9 calamities:
1 A.C.= The first major event that shaped Asarius was the fall-out between the twin goddesses. Their battle would spell the end of their gods coexisting with their followers. It also signaled the end of the flying city of "Iel" that after the battle hasn't been seen. It is heavily speculated that the city was destroyed.
2 A.C.= Luciel now banished in Appolyian manages to temporarily lift the veil between realms. Unable however to enter the continent in physical form herself. She decides to send Dremoras to invade. The invasion fails, stopped by primarily the help of the unification of the splintered northern human kingdoms and the help of powerful paladins. This unification leads to the beginning of the Holy Empire.
3 A.C. = The Third calamity spelled the end of the Holy Empire. Unclear succession and different noble factions betting on other heirs let the Holy Empire split off into 5 pieces: Southern Holy empire, Central Holy empire, Western Holy Empire, Eastern Holy Empire, and Northern Holy Empire.
4 A.C.= Plague of the Beastmen or better known as "The Dog's Cough." It was a plague that caused a high amount of Casualties throughout Asarius. It is widely believed that it originated from the beastmen. They were even resistant to the disease, making many believe that the beast men actually purposefully started the disease. A small problem was that the Beast men during the fourth Calamity were everywhere in the world. Not willing to let walking plague carriers breathe in their lands, the human and elvish kings decided to give them some land in the south-eastern corner. Letting them live there in isolation. The stereotype that all beast men are filthy and disease-ridden is still quite well known.
5 A.C.= Corruption of the western Holy empire. Having natural harsh territory and limited resources, the western empire had to go on the offensive to claim land. Their numbers dwindled, and the queen had to look for more immoral solutions. This led to a chain of events that cause the Invazauri. The Invazauri were unlike anything Asarius had seen, and the fifth calamity is easily considered the most dangerous calamity of all. The Invazauri is a virus that wants to infect everything it can and continue to spread. An individual that comes into contact with the disease will either become an Invazauri minion, Simply get devoured, or become an Invazauri Hivemind. An Invazauri Hivemind is an infected person that becomes a leader of the Invazauri minions sharing the desire to infect everything else, and if that wasn't bad enough, they are all incredibly powerful. Invazauri minions didn't die from the infection, but aren't capable enough of becoming a Hivemind. The Hivemind they are linked with has full control over their Hive minions. People who cannot handle the infection get devoured by the others as they become fuel to enhance the other Invazauri's strength.
6 A.C.= The Witch hunt, seeing the corruption of the west and its isolation. Regulations around magic and other scientific experiments have grown more stern.Two radical different groups of Sorceres began to form. One that wanted to maintain complete freedom of magic and another one believed in regulation. The one backing regulation managed to convince the necessary governments and established a building to facilitate this new, more controlled era of magic. The building was named "Drearoth". Sorceres who did not agree with the changes were called witches and were either locked up or killed.
7 A.C.= On an unsuspected day, the entire Northern Holy Empire was engulfed in flames. An empire burned to pieces. There are no survivors, and the land that is now eternally clouded with the ashen ground and the ashen sky is now called the ashen land.
8 A.C.= the earthquake that shifted the earth. An unidentified large earthquake destroyed large portions of society and claimed a lot of lives. The maesters are fascinated by this phenomenon, and it's considered the most fascinating natural phenomenon to date.
9 A.C.= Bloodletting of the ashen elves. The Ash elves, a race of proud elvish warriors focused on the more martial way of life and used to live in the desert. Their capital where a large part of their population resided was devoured by a gigantic earthworm monster. The remnants sought refuge with their elvish brethren, but instead of being welcomed were either enslaved or killed. Few alive still walk Genesias.
Now, you might wonder, "a lot of Holy empire stuff." Well that's because the maesters are mostly humans and for them, it would be like Romans seeing something happen to Rome whilst the elven society would, for example, be romans seeing something happen to Persia. They would care far more when it involved Rome.
Every calamity has different reasons and different opinions what I've written here is the general known situation, only the fifth calamity was really expanded upon since that was one where everyone agreed that the chances that it could have ended civilization were way too high.
Time durations
0 A.C. - 1A.C. 321 years 0-321
1 A.C. - 2 A.C 214 years 321-535
2 A.C. -3 A.C 413 years 535-948
3 A.C. - 4 A.C. 89 years 948-1037
4 A.C. - 5 A.C. 150 years 1037-1187
5 A.C. - 6 A.C. 79 years 1187-1266
6 A.C. - 7 A.C 233 years 1266-1499
7 A.C - 8 A.C 188 years 1499-1687
8 A.C. - 9 A.C. 102 years 1687-1789
9 A.C. - Present day 51 years 1789-1840
Total years after A.S. 1840
The last part is for family tree reasons. Since I can't add ACs on the program that I'm using I will simply use the total years.