"Shadow Due Date" is an informal, unofficial term given to the date after which a delinquent filer will be dropped from the Bulletin Board. It is thirty days after the extended due date (if the extension request was timely filed). The extension request is timely filed if filed by the end of the first business day following the original due date. Weekends count in the number of days, but they defer the due date of any 1934 Act Filing which would be due on a weekend until the first business day thereafter.
So for COPI (who never before has been delinquent - although frequently availing itself of an extension) the original due date was March 31, 2010, the ninetieth calendar day after December 31, 2009. March 31, 2010 was a Wednesday. The timely filed extension therefore extended the due date until Thursday, April 15, 2010. Thirty days from April 15, 2010 is May 15, 2010, which is a Saturday. The next following business day and the "Shadow Due Date" for COPI, after which they will be dropped from the Bulletin Board is Monday, May 17, 2010, by 17:30 hours, EDT. By rule, the actual Edgar transmission must be started by 5:29:59 PM and be completed in one unbroken transmission - (no electrical disruptions, etc.). If it meets those requirements, the transmission completion time may be after 5:30 PM.
On a few previous occasions - but not very recently, the SEC's Edgar System was so overloaded, and on one occasion there was a wide-spread power failure on the East Coast, the SEC altered the filing times, and therefore the filing date, to the next business day.
Once dropped from the Board, reinstatement is an involved process, not without out-of-pocket financial costs to say nothing about the effect on the PPS.