Where did u read or see that?
Says to me it runs whole October , only day/night cycle is only 2 weeks, but that says nothing about ToT,... at least to me it doesnt.
Eternal Night
The Eternal Night state is only active for the first and last weeks of the event. When active the entire game is locked in nighttime mode. This is not just a visual effect, all aspects of the game that depend on a day/night cycle are locked to the night side during the event. Enemies that only spawn at night spawn continuously during the event. Banisher, The Slayer, and Haunted badges (Hero side) and Pirate and Spectral badges (Villain side) are examples of badges for which hunting will be much easier during the event.
Note that some zones, such as Cimerora, The Hive and The Abyss are unaffected by Eternal Night.