1 3 34 NOW okay =========================: 34 34 NOW BAD ==========================: 34 34 finish ===========================; * A UNION * B: A 1970-01-01 02:00:01 B 1970-01-01 02:00:02 Event, Datetime A UNION * B: A 1970-01-01 02:00:01 B 1970-01-01 02:00:02 * A UNION Event, Datetime B: A 1970-01-01 02:00:01 B 1970-01-01 02:00:02 Event, Datetime A UNION Event, Datetime B: A 1970-01-01 02:00:01 B 1970-01-01 02:00:02