close.
Sitchin claimed that the Sumerians recorded previous passes of Nibiru. He stated that this (fictional) planet was on a 3,600 year orbit that brought it into the inner solar system, and that the next pass would be in 2,900, but that the Annunaki would be returning (via spaceship) in 2090.
Lieder claimed that her Planet X was Sitchin's 12th planet, but that it was returning in 2003. When her date came and went, she then claimed that the 'Zetas' had 'laid a trap for the establishment' by promoting the wrong date, and that it would return in 2006. When the 2006 date came, she claimed it had arrived, but was hidden, either behind the sun, or by clouds of magnetic dust, or something-or-other.
The whole Nibiru/Planet-X belief system was then co-opted by the 2012ers, who claim that this impossible and undetected planet will be responsible for the 2012 doomsday.