getting difference between two dates in php giving error - php

Question

i am trying to find difference between two dates in php, the first date is coming from my database (which is in datetime format), so i am converting it to date and then finding the difference using the current date. my code is like below:
$ret=mysqli_query($con,"select * from members");
$cnt=1;
while ($row=mysqli_fetch_array($ret))
{
$date_time = $row['date'];
$new_date = date("Y-m-d",strtotime($date_time));
$dates = date('Y-m-d');
$diff = $new_date->diff($dates);
echo $diff;
}
then i am getting the following error:
Uncaught Error: Call to a member function diff() on string in C:\xampp\htdocs\form\admin\members.php:123 Stack trace: #0 {main} thrown in C:\xampp\htdocs\form\admin\members.php on line 123
can anyone please tell me what i am doing here is wrong. thanks in advance

Answer 1

date function returns a string.
https://www.php.net/manual/en/function.date.php
You can use date_diff function to compare dates in string format
https://www.php.net/manual/en/function.date-diff.php
or use DateTime class which has method diff.
https://www.php.net/manual/en/class.datetime.php

Answer 2

Use date_diff function instead of the object notation here, DateTime object if you want your date to be Object

Answer 3

date() function returns a string. You need to create an object of DateTime class. Your loop should look something like this:
foreach ($ret as $row) {
$new_date = new \DateTime($row['date']);
$diff = $new_date->diff(new \DateTime());
var_dump($diff);
}