Rashi on the Former Prophets

In the eighteenth year [of the reign] of King Yerovom. One year after Rechovom’s death, in the twentieth year of Yerovom, Asa reigned. The third year of Nodov (Aviyam) is counted for King Asa as a year, and for him it is also counted.

And he rid [the land] of prostitutes. [Targum] Yonoson rendered, “and he abolished the prostitutes.”

He removed from her position of authority. From being queen.
For she had made a fearful image. Our Rabbis stated [that מפלצת is a combination of] מפליא ליצונתא [=extreme lasciviousness]. She made for it a phallic symbol, and she would copulate with it every day.

[However] the [private] altars he did not remove. The private altars upon which they had become accustomed to sacrifice to Heaven since Shiloh had been destroyed until the Beis [Hamikdosh] was built, when private altars were permissible, were not removed now, even though they were forbidden once the Beis [Hamikdosh] was built, and they were punished by premature death because of it.

There will be no exceptions. Even a bridegroom from his chamber, concerning whom it is stated, “he shall be free for his home one year.”

Two years. The second and the third [year] of Asa.

It was during the third year of Asa king of Yeudah, Bashah son of Achiyoh became king. The third year of Asa is counted for Nodov and Bashah.