Enderal:Document of the Holy Order concerning the Rifts in the Intercontinental Temporal Fabric
There is a well-founded suspicion that the unified time fabric in Vyn is no more, even worse, it is already “broken” since the Starfall in the first era. This means that the different continents, which were created with the impact of the celestial body, all exist in different timelines. Archeological researches of arcanists concerning objects from different continents led to very contradictory results. A conclusive explanation for this phenomenon is impossible if we take into account the huge timeframe between the Starfall and our present age.
In addition to that, the regents of the different continents created their own calendar for political reasons and to strengthen their authoritative profile. These calendars were often retroactively manipulated, sometimes substantially. For example, there is a good reason to believe that there were several centuries “inserted” into history after the founding of Nehrim's main city Erothin to make their own history deeper. We still do not know if this manipulation was done by Erodan himself or if one of his worldly governors made this change and Erodan only tolerated this decision because he didn't want to oppose the wishes of these humans. It's a fact that the downfall of Treomar was placed at the end of the 9th Millennial after Starfall in Nehrim's calendar, while Enderal's placed it in the year 8202.
Differences which did not stem from the many calendars but instead from different passing speeds of time couldn't be perceived by most humans because of the long time periods which were needed for these effects to show themselves. Additionally, the different timelines do not have a constant flow - they run next to each other like carriages whose horses trot in different speeds. There are times at which one carriage is faster, then it is the other way around or both are almost equally fast.
Last but not least it can be assumed that the guiding hand of the Light-Born - in their endless wisdom - ensures that travelers between the continents aren't affected by the temporal discrepancies any way that could lead to unbearable confusion of their mortal minds. Inodan, home of the Light-Born, is an enclave in which the time always runs with the same speed so that the Light-Born can preside over Vyn, free from the different timelines.
However, the most remarkable discrepancy of the timelines - in particular between Nehrim and Enderal - can be seen since the downfall of Treomar. After the death of Erodan, the now godless Nehrim took the event as a reason for introducing a new calendar, while Enderal continued to use the Starfall as its year 0. While a whole millennium was added in Nehrim's history books after Treomar's downfall, only 32 years passed in Enderal.
This difference cannot be explained by the general rift of the time fabric, nor by manipulative writing of history. Agents of the Holy Order have discovered that the temporal shifts seem to occur in bursts more than ever and so the meetings of Nehrimese and Endralean merchants in their respective harbors led to confusion on both sides. As the Nehrimese never had a strong interest in Enderal and its continent, paired with Nehrim's isolation after Erodan's death, this problem never became widespread knowledge - especially because of the discreet actions of several agents of the Holy Order.
One of the main reasons for these huge shifts is, of course, Erodan's fall and therewith the loss of the Light-Born governing Nehrim. Since then, Nehrim is torn with tyranny, conflicts and a general instability which also affected the magical fabric. The mage order which was responsible for Erodan's fall (and used unbelievable amounts of arcane energy for that) uses its sanctuaries since then to keep the aftereffects of their actions in check. In doing so, the disordered fibers of magic are focused and stabilized, though it also leads to several magical disorders all around the continent. In Nehrim's Southrealm this magical contamination already gave birth to the baleful nexus crystals, a sign that a big part of the continent is already torn out from the natural embedment of the fibers of magic - a chaos which occasionally becomes noticeable in other regions of Nehrim, too.
These disorders are responsible for the entrance of different eventualities into this world, which are at times even taken as reality by Nehrim's inhabitants. That means that the extreme rifts in the temporal fabric since Treomar's downfall are a combination of the actual change of time flow and collective illusion. It appears that the members of the magic order in Nehrim are able to withstand these disorders with their wild magic - they use it to understand and even control these disorders. There are no records about all of this, neither from the mage order, nor from their adversary, the chancellor Barateon. That means that both sides want to keep this a secret, most likely because both played a part in the uprisings against the Light-Born in the past.
Since the fall of the Light-Born (see the eponymic document for further details) the enormous temporal discrepancy between Enderal and Nehrim gave way to a steadier time flow. There is reason to assume that the total annihilation of the Light-Born repaired the temporal fabric once more. Though the chaos which found its way into Enderal since then points to some much more sinister consequences in the long run.
According to reports of the Holy Order's agents, Narathzul Arantheal quickly misused the temporal discrepancy for propaganda purposes after his rescue. Although he wasn't under the effects of the temporal conditions on the continent's surface in his underground prison guarded by the Seraphim, he claimed that he lived there for a whole millennium to obtain a more mysterious and mightier aura in the eyes of his followers and enemies alike.
Likewise, the imprisonment of Tealor Arantheal in the halls of the former Creator's Temple didn't proceed according to the temporal conditions of the outside world. Nonetheless the decades in total darkness were a heavy trial for him - but he mastered it with his power of faith and his steadfast path-abidingness.