Plus Deutsch is German for German, henceforth the explaination on why the Pennsylvania Dutch are called that when they are really German and not Dutch. The Dutch from the Netherlands also got their ethnic name derived from the German term Deutsch as well believe it or not. If you're Dutch, then you are from Denmark.
1 Deadline for filing a 2015 personal, partnership, or calendar year estates/trusts tax returns or extension.  The return or extension must be postmarked or transmitted for e-filing by Monday, April 18, 2016 (April 19 for Maine and Massachusetts residents).
General Instructions. Colorado personal income tax returns are due by April 15. If you cannot file by that date, you can get an automatic state tax extension. A Colorado personal extension will give you 6 extra months to file, moving your deadline to October 15. There is no form or application to request a tax extension from the State of Colorado. The only requirement is that at least 90% of your tax liability must be paid by the original deadline (April 15) to avoid late fees.