Here is the paragraph from their last report. This is available at www.blackstone.com
The Blackstone Group L.P. has declared a quarterly distribution of $0.30 per common unit to record
holders of common units at the close of business on March 15, 2010. This distribution will be paid on
March 31, 2010.
When companies announce dividend date they only announce the stockholder of record (SOR) date because the ex date is established by the exchange. But, if you know the SOR date, you can establish the ex date. I go back two business days for the ex date. BX, SOR is 15 Mar, Ex is 11 Mar. Info is at SEC website.