class Holiday extends Model
{
    protected $table = 'holidays';
    protected $primaryKey = 'holiday_id';
    public $timestamps = false;
    public function dates(){
        return $this->hasOne('AppHolidayDates', 'holiday_id');
    }
    public function images(){
        return $this->hasMany('AppHolidayImages', 'holiday_id');
    }
    public function info(){
        return $this->hasOne('AppHolidayInfo', 'holiday_id');
    }
    public function pricing(){
        return $this->hasOne('AppHolidayPricing', 'holiday_id');
    }
}

class HolidayInfo extends Model
{
    protected $table = 'holiday_info';
    public $timestamps = false;
    protected $primaryKey = 'holiday_id';
    public function holiday(){
        return $this->hasOne('AppHoliday', 'holiday_id');
    }
}

$holidays = Holidays::with('info')->get();

Holidays::where('country', $country)->with('info')->get();

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'country' in 'where clause' (SQL: select * from holidays where country = australia)

SELECT * from holidays JOIN holiday_info ON holidays.holiday_id = holiday_info.holiday_id

public function info(){
        return $this->hasOne('AppHolidayInfo', 'holiday_id');
    }

Holiday::where(your condition)->with('info')->get();

public function info(){
        return $this->hasOne('AppHolidayInfo', 'holiday_id','holiday_id');
    }

hasOne($related, $foreignKey, $localKey )

$holidays = Holiday::where(your condition)->get();

foreach($holidays as $holiday){
    $holiday->info->youInfoFieldHere
}