If you’re married at 11:59 pm on December 31 you’re married for the full year.

Get both your tax forms for last year and a copy of TurboTax and rerun the numbers as if you were married. If you’re just W2 employees do the same thing this year with your most recent pay stub. If it saves you money and you’re comfortable no one will call off the wedding, just do it.

My wife and I did something similar. We had a wedding planned for June, I ran the numbers in November and realized it would save us $9000 in taxes if we got married before the end of the year. We had a small civil ceremony after Christmas with our family in attendance, then did the real wedding the following summer. Used the tax refund for our honeymoon.