The Employee Benefits Security Administration (EBSA) has published form M-1 for 2007

The form is almost identical to the 2006 Form M-1 and is due March 1, 2008. As with most tax document, payments and forms that are due on a specific day if that day fall on a weekend it is due the following Monday. So the 2007 M-1 Form due on March 1, 200 a Saturday will be due on Monday march 4th. A one-time extension is available but it is due before the initial filling.

Form M-1