9 Collier on Bankruptcy P 1011.03
Summary
A response to an involuntary petition, containing defenses or objections to the petition, is presented in the manner prescribed by Rule 12 of the Federal Rules of Civil Procedure,1 and must be filed and served within 21 days after service of the summons if the summons was served personally or by mail. If the 21st day falls on a weekend or holiday, the putative debtor or other responding party has until the next business day to file and serve the response.2
The court may, in its discretion, permit a party to file a response after the 21-day period has expired.3
The responding party must show cause and show that the failure to file a timely answer was due to excusable neglect.4