Waht is tax due date when living oversea? Today Oct. 17 or Dec. 15 (because of oversea, you get 2 months extra)?

Remember that e-filing will be closed at midnight tonight on October 17.   So your return can only by filed by mail if you are past that date.

 

To use the 2-month extension for U.S. Citizens and Resident Aliens Abroad you will have to file by mail. 

 

 You will be allowed the extension if you are a U.S. citizen or resident alien and on the regular due date of your return:

• You are living outside of the United States and Puerto Rico and your main place of business or post of duty is outside the United States and Puerto Rico, or
• You are in military or naval service on duty outside the United States and Puerto Rico

To use this automatic 2-month extension, you must attach a statement to your return explaining which of the two situations qualified you for the extension. More here.

Clarification needed .... the original answer described the automatic 2 month extension for those overseas or in the Military.  To get the second extension after the first 6 month extension you must  mail in a request by 10/17.  Just adding an explanation to the mailed in return will not work.  Per the IRS : 

 

In addition to the 6-month extension (automatic 2-month and additional automatic 4-month extensions), a taxpayer  can request a discretionary 2-month additional extension of time to file their return to December 15, 2022, if they are a calendar-year taxpayer.

 

To request this extension, you  must send the IRS a letter explaining the reasons why you need the additional 2 months. You must send the letter by the extended due date (October 17, 2022, if you are  a calendar-year taxpayer) to the following address:

 

Department of the Treasury
Internal Revenue Service Center
Austin, TX 73301-0045

You won’t receive any notification from the IRS unless his request is denied.

https://www.irs.gov/publications/p3