Tax returns, and any taxes owed, must be filed online or postmarked by today in order to avoid steep tax penalties. The U.S. Post Office in the Browne’s Addition Rosauers store, 1808 W. Third Ave., will be open until midnight tonight to accommodate last-minute filers. In addition, the Post Office in the Rosauers on 29th Avenue will be open until 9 p.m. For more information about postal locations and hours, go to www.usps.com. Taxpayers who need extra time to file their federal returns this year can file Form 4868 to request an automatic extension through the Internal Revenue Service Free File. For information, go to the IRS Web site.