CREATE TABLE table_19340 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Time  (  ET  ) " TEXT, "TV" TEXT, "Result" TEXT, "Record" TEXT, "Game Site" TEXT)

Name the number of date for shea stadium
SELECT COUNT("Date") FROM table_19340 WHERE "Game Site" = 'Shea Stadium'
SELECT COUNT("Date") FROM "table_19340" WHERE "Game Site" = 'Shea Stadium'