I guess the problem I have with this is that if contribution in following tax year counts in prior tax year for purposes of assessing what portion of deductible contributions are taxable when converting a particular traditional IRA with non deductible contributions to a Roth IRA, this does not count in assessment of total fair market value of all traditional and SEP IRAs which is assessed as of Dec 31 2020. It just seems a loophole in worksheet that potentially benefits tax payer if they delay making contribution to an IRA for 2020 instead of on Dec 31 to Jan 1 of following year!
