How to only keep posts with dates in between other

Question

I have some posts with some custom fields where I have a date in a string format, so I loop my posts and I convert each of them as a Date, then I do some bit to have them in order by date:

foreach($posts as $post) {
    $postid = $post->ID;
    $myDate = \DateTime::createFromFormat('j-n-Y', get_post_meta($postid, 'usp-custom-80', true));
    $postOrdered[$postid] = \DateTime::createFromFormat('j-n-Y', get_post_meta($postid, 'usp-custom-80', true));
    wp_reset_query();
}
arsort($postOrdered);
var_export($postOrdered);

So I am attaching the date together with the ids and that gives us:

array ( 128288 => DateTime::__set_state(array( 'date' => '2017-08-20 20:36:02.000000', 'timezone_type' => 3, 'timezone' => 'UTC', )), 128166 => DateTime::__set_state(array( 'date' => '2017-08-17 20:36:02.000000', 'timezone_type' => 3, 'timezone' => 'UTC', )), 128308 => 
DateTime::__set_state(array( 'date' => '2017-08-05 20:36:02.000000', DateTime::__set_state(array( 'date' => '2000-03-20 20:36:02.000000', 
DateTime::__set_state(array( 'date' => '1978-05-11 20:36:02.000000', 'timezone_type' => 3, 'timezone' => 'UTC', )), 128295 => 
DateTime::__set_state(array( 'date' => '1978-04-10 20:36:02.000000', 'timezone_type' => 3, 'timezone' => 'UTC', )), 128337 =>
 DateTime::__set_state(array( 'date' => '1978-03-16 20:36:02.000000', 'timezone_type' => 3, 'timezone' => 'UTC', )), 128315 => DateTime::__set_state(array( 'date' => '1976-08-10 20:36:02.000000', 'timezone_type' => 3, 'timezone' => 'UTC', )), 128290 => DateTime::__set_state(array( 'date' => '1970-04-12 20:36:02.000000', 'timezone_type' => 3, 'timezone' => 'UTC', )), )

OK now what we do is GET some $start and $end dates from a form using GET

$start = $_GET['start']; 
$end = $_GET['end'];
$start  = \DateTime::createFromFormat('j-n-Y', $start);
$end  = \DateTime::createFromFormat('j-n-Y', $end);
var_dump($start);
var_dump($end);

And that gives us:

object(DateTime)#8267 (3) { ["date"]=> string(26) "2019-02-01 20:51:56.000000" ["timezone_type"]=> int(3) ["timezone"]=> string(3) "UTC" } 
object(DateTime)#7974 (3) { ["date"]=> string(26) "2019-02-05 20:51:56.000000" ["timezone_type"]=> int(3) ["timezone"]=> string(3) "UTC" }

Now what i am trying to do is a simple check if any of those posts have any date in between our $start and $end and display them order ASC or DESC

Literally something like

if ( ( $myDate >= $start) && ( $myDate <= $end) ) {
 ...my posts...

But that still gives us all posts regardless

Answer 1

You can just compare DateTime objects directly, so your code can be written as:

$start = \DateTime::createFromFormat('j-n-Y', $_GET['start']);
$end = \DateTime::createFromFormat('j-n-Y', $_GET['end']);
foreach($posts as $post) {
    $postid = $post->ID;
    $myDate = \DateTime::createFromFormat('j-n-Y', get_post_meta($postid, 'usp-custom-80', true));
    if (($myDate >= $start) && ($myDate <= $end)) {
        $postOrdered[$postid] = (int)$myDate->format('U');
    }
    wp_reset_query();
}

Note that all the dates on your posts are before 2019, so you will need to adjust your $start value to see any posts in the output.

To get a sorted list of unique dates, use this code after the foreach loop:

$postOrdered = array_unique($postOrdered);
arsort($postOrdered);