Knowin when and what you have to file can save you a lot of headaches at tax time. To avoid paying penalties, mark your calendar with the following important tax deadlines.

January 16, 2017 4th Quarter 2016 Estimated Tax Payment Due
If you are self-employed or have other fourth-quarter income that requires you to pay quarterly estimated taxes, get them postmarked by January 15, 2017 tax deadline.
April 18, 2017 Individual Tax Returns Due for Tax Year 2016
If you haven’t applied for an extension, e-file or postmark your individual tax returns by midnight April 18, 2016.
Individual Tax Return Extension Form Due for Tax Year 2016
Need more time to prepare your tax return? File your request for a tax extension by April 18 to push your tax deadline back to October 17, 2017.
1st Quarter 2017 Estimated Tax Payment Due
If you are self-employed or have other first-quarter income that requires you to pay quarterly estimated taxes, get your Form 1040-ES postmarked by April 18, 2017 tax deadline.
Last Day to make a 2016 IRA Contribution
If you haven’t already funded your retirement account for 2016, do so by April 18, 2017. That’s the deadline for a contribution to a traditional IRA, deductible or not, and a Roth IRA. However, if you have a Keogh or SEP and you get a filing extension to October 17, 2017, you can wait until then to put 2016 money into those accounts.
June 15, 2017 2nd Quarter 2017 Estimated Tax Payment Due
If you are self-employed or have other second-quarter income that requires you to pay quarterly estimated taxes, make sure your payment is postmarked by June 15, 2017 tax deadline.
September 15, 2017 3rd Quarter 2017 Estimated Tax Payment Due
If you are self-employed or have other third-quarter income that requires you to pay quarterly estimated taxes, make sure your third quarter payment is postmarked by Sept. 15, 2017 tax deadline.
October 16, 2017 Extended Individual Tax Returns Due
If you got a filing extension on your 2016 tax return, you need to get it completed and postmarked by October 17, 2017.
Last Chance to Recharacterize 2016 Roth IRA Conversion
If you converted a traditional IRA to a Roth during 2016 and paid tax on the conversion with your 2016 return, October 16, 2017 is the deadline for recharacterizing (undoing) the conversion. Doing so could save you money if the IRA has lost money since the time of the original conversion.
January 15, 2018 4th Quarter 2017 Estimated Tax Payment Due
If you are self-employed or have other fourth-quarter income that requires you to pay quarterly estimated taxes, get them postmarked by January 14, 2018 tax deadline.

Source: Intuit Turbo Tax