when should i leave home if i want to arrive at the music concert at 9 pm?
[IN:GET_ESTIMATED_DEPARTURE when should i leave [SL:SOURCE [IN:GET_LOCATION_HOME home ] ] if i want to arrive at [SL:DESTINATION [IN:GET_EVENT [SL:CATEGORY_EVENT the music concert ] ] ] [SL:DATE_TIME_ARRIVAL at 9 pm ] ? ]