409A Tax Reporting

[ERISA-Bubs]

The regs say a payment will still be treated as being paid on the designated payment date if paid the later of (1) the end of the year of the designated payment date, or (2) the 15th day of the 3rd month following the payment date.

Focusing on (2) above, say a payment is due 12/31/2012. Payment is still treated as paid on the payment date if paid on, say, 2/5/2013.

Question: Should this be treated as taxable income on 12/31/2012 (the date the payment is treated as being paid under 409A) or on 2/5/2013 (the date actually paid)?