The ideal time to contribute to a Roth IRA is when you're young and poor. In other words, if you're a student and in your 20s earning less than the maximum income limit, you should be contributing.

However, if you're about the 22% federal marginal income tax rate, it's a push.

Tax diversification in retirement is important! 

https://www.financialsamurai.com/disadvantages-of-the-roth-ira-not-all-is-what-it-seems/

https://www.financialsamurai.com/never-contribute-to-roth-ira/