code: public Date getLastModificationDate() {
  		if (this.year == 0 || this.month == 0 || this.day == 0){
  			return null;
  		}
  		try {
  			Calendar calendar = Calendar.getInstance();
  			calendar.set(this.year, this.month, this.day, 0, 0, 0);
  			calendar.set(Calendar.MILLISECOND, 0);
  			return calendar.getTime();
  		}
  		catch (Exception e) {
  			return null;
  		}
  	}
docs: Gets the date the file was modified
  @return The date de file was created