Update existing post dates to random dates

Question

I want to change the date of publication of my already published posts to random dates within the range starting from 2015 till today.

How to do this in WordPress using CODE.

Answer 1

Question

How to change the post date to a randomly generated date?

Answer

This is fairly straightforward. What I did was to create a plugin that upon activation get all the posts, loops through them, generates a random date, and updates the post with that date.

<?php
/**
 * Plugin Name: WPSE 259750 Random Dates
 * Description: On activation, change the dates of all posts to random dates
 */

//* We want to do this only once, so add hook to plugin activation
register_activation_hook( __FILE__ , 'wpse_259750_activation' );
function wpse_259750_activation() {

  //* Get all the posts
  $posts = get_posts( array( 'numberposts' => -1, 'post_status' => 'any' ) );
  foreach( $posts as $post ) {

    //* Generate a random date between January 1st, 2015 and now
    $random_date = mt_rand( strtotime( '1 January 2015' ), time() );
    $date_format = 'Y-m-d H:i:s';

    //* Format the date that WordPress likes
    $post_date = date( $date_format, $random_date );

    //* We only want to update the post date
    $update = array(
      'ID' => $post->ID,
      'post_date' => $post_date,
      'post_date_gmt' => null,
    );

    //* Update the post
    wp_update_post( $update );
  }
}