Harvard University officials aren't setting an official extension date for early action applications, but they are reminding applicants that they are always flexible with deadlines when students face hardship. Here's the note from the Office of Admissions website:
With the approach of Hurricane Sandy here on the East Coast of the United States, we want you to be aware of our longstanding flexibility on Early Action and Regular Action deadlines for submitting applications and supporting materials from teachers and guidance counselors. If there is a good reason for not being able to meet a deadline (whether it be a natural disaster such as Hurricane Sandy or a personal challenge), we are happy to accept late applications and support materials. All you and your recommenders need to do is explain the reason in a brief note to email@example.com.