It’s Tax Day. If you’ve procrastinated, there are some things you should know.

Monday is Tax Day, offering plenty of chances for agony and ecstasy.Some merchants offer deals or freebies to ease the pain. Taxpayer groups perhaps increase misery with reports showing just how long it takes to work off tax bills. And the U.S. Postal Service urges care in filing to avoid penalties.Income tax returns are due by midnight if filed online and require a Monday postmark if filed by mail. Filers may obtain an automatic extension, if needed, by filing for one by the deadline.The U.S. P