ChartJS将字符串中的日期视为数字

I am trying to get some strings from a csv file, to put under a graph from chartjs.

I wrote this php function:

function getTitle($id) {
 $stations = fopen("stations.csv", 'r');
 //$csv_data = fopen(date("G") . '.csv', 'r');
 $csv_data = fopen('16.csv', 'r'); //fopen("/mnt/weather-data/" . 
 date("Y/m/d/G") . ".csv", 'r');
 $data = array();
 $DAY_LENGTH = 60 * 60;
 $currentDate = date('U');

while (($line = fgetcsv($csv_data)) !== FALSE) {
    $date = date('U', strtotime($line[1]));
    if ($date >= ($currentDate-$DAY_LENGTH) && $line[2] == $id) {
        array_push($data, $line[0]);
    }
}

for ($i = 0; $i < count($data); $i++) {
    echo $data[$i] . ",";
}
fclose($stations);
fclose($csv_data);
}

which is working fine, everywhere I call this function, it prints the necesarry strings, which is a date, so 2018-02-08 for example.

When I try to call this function in the label part where i need them in ChartJS. it returns this date as a sum, so like 2018-02-08 will return as 2008.

labels: [<?php getTitle(($_GET['id']))?>],

What is it what I'm doing wrong?

Another problem when I try to change $line[0] to $line[1] which is a time with the following format: 20:17:36, my whole application stops working..

Hope anyone can help me!!

The Problem with your code is that the echo will just output the content of the variable but as you are parsing it's value into a javascript array you need to surround your value with quotation marks. So if you change

for ($i = 0; $i < count($data); $i++) {
    echo $data[$i] . ",";
}

into

for ($i = 0; $i < count($data); $i++) {
    echo "'" . $data[$i] . "',";
}

it should work. This will also solve your other problem. So with this change you should also be able to use the time.