Section 1031 exchanges must be completed within 180 days after the sale of replacement property. The exception is when the April income tax filing deadline falls within that 180 day period, in which case the April filing deadline trumps the 180 day deadline. In other words, your 1031 closing deadline is now the April tax filing deadline.
To realize the full 180 day exchange period, you must file an extension with the IRS. If you already filed your tax return, you can still claim your 1031 exchange on an amended tax return. Your best idea is to discuss this with your CPA or tax advisor, as well as your Qualified Intermediary, immediately.