If your posts are displaying the date of creation or modification, but you want to set the specific date for publication your post, then you need to do next:
1. Copy this function and insert into functions.php file of your child theme
function seosight_posted_time( $icon = true){
$time_string = '<time class="entry-date published updated" datetime="%1$s">%2$s</time>';
$time_string = sprintf( $time_string,
esc_attr( get_the_date( 'c' ) ),
esc_html( get_the_date() )
);
$icon_html = (true === $icon) ? '<i class="seoicon-clock"></i>' : '';
return sprintf(
'<span class="post__date">' . $icon_html . $time_string . '</span>'
);
}
2. Then you can change any date for the post in the editor.