subscription what if you need foreach in  [] ? 
$data[] = [
        "name" => $key["add_hour"].":00",
        "data" => [[  
          "x" => (int) $key["add_date"],
          "y" => (int) $key["times"]
        ]
        //  x  y]
      ];like this
$data [] = [
]    "name" => $key["add_hour"].":00",
    "data" => [[  
      "x" => (int) $key["add_date"],
      "y" => (int) $key["times"]
    ],
    [  
      "x" => (int) $key["add_date"],
      "y" => (int) $key["times"]
    ],
    [  
      "x" => (int) $key["add_date"],
      "y" => (int) $key["times"]
    ]]
  ];