Board Thread:Ninjago Wiki News/@comment-25095204-20140703085642/@comment-26537965-20180324145534

Given that Season 6 and Day of the Departed  take place like 3-4 years after Season 2 (this is confirmed by Tommy Andreasen),  Season 7 took place right after Day of the Departed, and Season 8 was a year after 7, only 4-5 years have passed, not 8.