CREATE TABLE table_72936 ("Season" TEXT, "Date Released" TEXT, "# Of Episodes" FLOAT, "# Of Discs" FLOAT, "Special Features" TEXT)

On how many dates was the complete 4th series released?
SELECT COUNT("Date Released") FROM table_72936 WHERE "Season" = 'The Complete 4th Series'
SELECT COUNT("Date Released") FROM "table_72936" WHERE "Season" = 'The Complete 4th Series'