What is today's deadline to file a tax extension?

The deadline for a federal extension depends on the return type and current IRS calendar.

Personal returns

For most individual returns, file Form 4868 by the original federal return due date. If the due date falls on a weekend or legal holiday, the next business day generally applies. Check the current IRS deadline rather than relying on a fixed time zone or date.

Business returns

Form 7004 deadlines vary by return type, entity, and tax year. File Form 7004 on or before the applicable original return due date.

For more detail, see Federal tax deadlines and extensions: individual returns or Business tax deadlines, Form 7004 extensions, and late filing.