public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof Hour)) {
            return false;
        }
        Hour that = (Hour) obj;
        if (this.hour != that.hour) {
            return false;
        }
        if (!this.day.equals(that.day)) {
            return false;
        }
        return true;