CREATE TABLE table_28796 ("Episode" FLOAT, "Title" TEXT, "Writer" TEXT, "Director" TEXT, "Original airdate" TEXT, "Ratings  ( Kanto ) " TEXT, "Ratings  ( Kansai ) " TEXT)

What is the original air date for the writer tanaka shinichi?
SELECT "Original airdate" FROM table_28796 WHERE "Writer" = 'Tanaka Shinichi'
SELECT "Original airdate" FROM "table_28796" WHERE "Writer" = 'Tanaka Shinichi'