What is the latest date you can get married and still file MFJ? Do you have to get married in the previous calendar year or can you get married prior to April 15?

[Critter · Accepted solution]

If you get married on 12/31 right before the stroke of midnight then you are considered married for the entire year for income tax purposes.  Same for getting a divorce.   

This is not something you can do "by the filing deadline" to get it to effect the prior year's return like an IRA contribution.