Set meta field to publish date + 2 weeks

Question

I have a meta field called postexpiry, and I want to set the value to the publish date, + 2 weeks. So if today were October 3rd, I want the field to be set to October 17th.

I was thinking about creating a hook to the publish_post filter, but I am not sure how to add 2 weeks on to get_the_date().

I know with php I can do something like this $dateInTwoWeeks = strtotime('+2 weeks'); but I'm not sure how to use that with get_the_date()

Thanks!

UPDATE

I tried the following code, but it didn't do anything:

function dp_expiry() {

$dp_new_expiry_date = strtotime( '+2 weeks', strtotime( $post->post_date ) );
update_post_meta( get_the_ID(), 'postexpiry', $dp_new_expiry_date );
}

add_action( 'publish_post', 'dp_expiry' );

Also, my theme requires that the date be in yyyy-mm-dd format.

UPDATE 2

This code outputs "1209600" to the field. Any ideas? Thanks!

add_action('publish_post', 'dp_expiry');
function dp_expiry( $data ) {

$dp_new_expiry_date = strtotime( '+2 weeks', strtotime( $post->post_date ) );

update_post_meta( $data['post_id'], 'postexpiry', $dp_new_expiry_date );
}

Answer 1

Try this:

add_action('publish_post', 'dp_expiry');
function dp_expiry( $data ) {
    /*adds 2 weeks onto the current date in unix epoch format*/
$dp_new_expiry_date = (strtotime( current_time( 'mysql' ) ) + 1209600);
        /*converts unix timstamp back to yyyy-mm-dd format like you required*/
    $dp_new_expiry_date_conv = date("Y-m-d", $dp_new_expiry_date);
update_post_meta( $data['post_id'], 'postexpiry', $dp_new_expiry_date_conv );
}

Answer 2

get_the_ID() is a loop function and might not work here. You should use the parameters of your callback instead:

function dp_expiry( $ID, $post ) {

    $dp_new_expiry_date = strtotime( '+2 weeks', strtotime( $post->post_date ) );

    update_post_meta( $ID, 'postexpiry', $dp_new_expiry_date );
}

add_action( 'publish_post', 'dp_expiry', 10, 2 );

publish_post only works for posts, not pages. You can use publish_{post_type} for a custom post type.