Tuesday is Tax Day, the deadline for filing federal income tax returns. (And yes, it’s really important to pay on time.) The dreaded day usually falls on April 15, but due to a combination of the 15th falling on a Sunday and a Washington, D.C., holiday, you’ve had two extra days to get it done. If your return is hopelessly snarled, don’t despair: Here’s what you need to know about filing a tax extension. Just remember: Even if you get an extension on filing, you still must pay what you owe by Tuesday. And whether you owe money or are getting a refund, you can still cash in: These businesses are marking the day with deals and freebies.