When do I pay taxes on earnings from a ROTH to Traditional re-characterization?

[crabanillo]

I did an excess contribution of $6000 to my ROTH IRA in 2019 - which I re-characterized (+earnings) to a Traditional IRA in February 2020. For the earnings that were re-characterized along with the excess contribution, do I have to pay tax on them in the 2019 return, 2020 return or when I get a distribution?

[MinhT1]

Please read this TurboTax answer by dmertz which addresses your question.