University of PennsylvaniaのLL.M.出願締め切り日です。
https://www.law.upenn.edu/admissions/grad/admissions.php

■Early Notification 2015/11/15
LLM and LLCM applications must be complete by November 15 for “Early Notification.”  Early Notification Applicants will be accepted, rejected, or deferred for further consideration  by February 1. (We will begin accepting applications on September 1.)

■Regular Notification 2015/12/15
LLM and LLCM applications are due by December 15.  Applicants will be accepted, rejected or wait-listed by mid-March.

If you miss the deadline, you can request a deadline extension. Late applications require an additional $25 late fee.　このように、Deadline Extensionに関する嘆願フォームを同校へ提出することができます。
https://www.law.upenn.edu/admissions/grad/frequentlyaskedquestions/forms/deadline-extension.php

以下、Deadline Extensionフォーム上の記載内容をご確認ください。
Applications are reviewed upon completion and applicants are admitted on a rolling basis.  And so, even if your request for an extension is granted, please note the later an application is completed, the greater the disadvantage to the applicant.

Disadvantageな状況を自ら設定しないよう、Regular Deadlineには出願手続きを終了させてください。