Among all the flights scheduled to depart from John F. Kennedy International on 2018/8/1, when was the earliest one scheduled to depart?
depart from refers to ORIGIN; John F. Kennedy International refers to Description = 'New York, NY: John F. Kennedy International'; on 2018/8/1 refers to FL_DATE = '2018/8/1'; earliest one scheduled to depart refers to MIN(DEP_TIME);
SELECT T2.DEP_TIME FROM Airports AS T1 INNER JOIN Airlines AS T2 ON T1.Code = T2.ORIGIN WHERE T2.FL_DATE = '2018/8/1' AND T1.Description = 'New York, NY: John F. Kennedy International' AND T2.DEP_TIME IS NOT NULL ORDER BY T2.DEP_TIME ASC LIMIT 1