int State = LOW;
long previousMillis = 0;

long interval = 1000;
long totalTime = 60000;

void setup() {

}


void loop() {

  unsigned long currentMillis = millis();
  //***************************************************
  // start of TotalTime
  if (currentMillis < totalTime) {
    if (currentMillis - previousMillis > interval) {
      previousMillis = currentMillis;
      if (State == LOW) {
        State = HIGH;
        //front
      }
      else {
        State = LOW;
        //back
      }
    }
  }//end of TotalTime
  //***************************************************
  else{
    //stop
  }
}// end of loop