I agree.  I would really like to see that link to IRS-provided information regarding Texans having a 5/17 deadline for Form 4868.  Texas received the extension to 6/15 before the rest of the US received anything, and there are no references to the 5/17 date in any IRS information provided on their website in regards to Texas.  In fact, the IRS refers to all deadlines regarding Texas returns moving to 6/15.  That would also include the extension deadline. Please provide evidence to the contrary.