CREATE TABLE table_name_55 (date VARCHAR2, result VARCHAR2, battle VARCHAR2)

What is the Date of the Bulgarian Victory at the Battle of Arcadiopolis?
SELECT date FROM table_name_55 WHERE result = "bulgarian victory" AND battle = "battle of arcadiopolis"
SELECT "date" FROM "table_name_55" WHERE "battle of arcadiopolis" = "battle" AND "bulgarian victory" = "result"