Checking by means of :
Example: ID 1 usually have 2 sets of number (1 or 2) and have 20 or less control numbers. Control number+date+time would not be overlap with another control number.
Example, Scenario 1:
ID 1, NUMBER 1 , Control number 1 Date+Time ON 8/18/2013 9:00, Date+Time OFF 8/18/2013 8:00, this is overlap.
Scenario 2: ID 1, NUMBER 1 , Control number 2 Date+Time ON 8/18/2013 21:00, Date+Time OFF 8/19/2013 03:00
ID 1, NUMBER 1 , Control number 3 Date+Time ON 8/19/2013 2:00, Date+Time OFF 8/9/2013 8:00, this is overlap.