You can file a 2014 tax return at any time. For a tax refund the 2014 return has to be filed on or before April 17, 2018.
Go to this TurboTax website to purchase a download of the 2014 desktop editions - https://turbotax.intuit.com/personal-taxes/past-years-products/2014/
A 2014 tax return can only be printed and mailed, it cannot be e-filed.