Switches,State,Intime,Outtime

sw3,1,9:00:00,10:40:00
sw2,1,9:30:00,10:15:00
sw1,1,10:00:00,11:00:00
sw2,1,10:20:00,10:30:00

10:00                           11:00
              sw1 |-----------------------------------|
       9:30       10:15   10:20     10:30
     sw2 |-------------|      |-------|
 9:00                                     10:40
sw3 |----------------------------------------|