If you were an employee and received wages subject to U.S. income tax withholding, file Form 1040NR by the 15th day of the 4th month after your tax year ends. A return for the 2013 calendar year is due by April 15, 2014.
If you did not receive wages as an employee subject to U.S. income tax withholding, file Form 1040NR by the 15th day of the 6th month after your tax year ends. A return for the 2013 calendar year is due by June 15, 2014.
However, the above IRS foreign filing deadlines relate to your federal taxes. The state of Arizona requires your state return to be filed by April 15th for a calendar year taxpayer. In addition, other states may have different filing deadlines.
Six month extensions can be filed that will give you additional time. But please be aware, an extension is merely an extension of time to file, but not to pay your taxes. So if you owe, you will have penalties and interest.
Since the deadline for US resident taxpayers is April 15th, our firm spends the majority of our time dealing with US taxpayers up to that deadline. For this reason, most of our non resident clients file six month extensions that give them additional time to file Arizona returns. Assuming this is the case, we then file our non resident returns between April 15th and June 15th.