Comparing Dates from custom field

Question

I am trying to compare dates from a custom field. I have them stored as something like "20121125". If the date has expired, a placeholder image will be used, if not, the default thumbnail will be used. Any advice is appreciated.

<?php
$html = "";
$key = get_post_meta($post->ID, 'Due', true);
$date = date('ymd');
if ($key >= $date) {
     the_post_thumbnail('medium');
} else {
    $html .= '<img src="http://exampleimage.com" alt="">';
}
return $html;
?>

Answer 1

Well, the exact server time/timestamp can be retrieve with current_time function. And comparing your date format, it would need to be Ymd. So combining these two thing, the proper comparison for you should be -

$key = get_post_meta( $post->ID, 'Due', true );
$date = date('Ymd', current_time('timestamp') );

if( $key >= $date )
{
    // note to retrive the post thumbnail, you need to use get_the_post_thumbnail,
    // as the_post_thumbnail function actually echo the output
    $html .= get_the_post_thumbnail(null, 'medium');
}
else 
{
    $html .= '<img src="http://exampleimage.com" alt="">';
}
return $html;

Now, there could be one question in which timezone you are saving the date in the post meta. If the value is sanitized with the server time (as the post_date value is saved), then this is perfect comparison.

Answer 2

You can try this:

<?php
$html = "";
$key = get_post_meta($post->ID, 'Due', true);
date_default_timezone_set('Africa/Lagos'); //Only if needed. Change this for your timezone
if (strtotime($key) >= time()) {
     the_post_thumbnail('medium');
} else {
    $html .= '<img src="http://exampleimage.com" alt="">';
}
return $html;
?>

Here we are using the strtotime function to help us compare these two dates.

You can find more information here:

• Comparing dates in PHP
• Change the default timezone

Hope it helps.

Answer 3

You can store the date after coonverting to timestamp using custom fields(i.e. in post_meta table). By doing so you will be able to compare dates easily. Then you can use your code as follows:

<?php
$html = "";
$stored_timestamp = get_post_meta($post->ID, 'Due', true);
$current_timestamp = strtotime(date('Y-m-d'));
if ($stored_timestamp >= $current_timestamp) {
    the_post_thumbnail('medium');
} else {
    $html .= '<img src="http://exampleimage.com" alt="">';
}
return $html;
?>

Store timestamp as:

update_post_meta($post->ID,'Due',strtotime(date('Y-m-d'));