Code generated by Bing to use year/month/day directories instead of year/month

year-month-day-uploads.php

<?php
/*
Plugin Name: Custom Upload Directory
Description: A plugin that stores uploaded files in year/month/day directories
Version: 1.0
Author: Bing
*/

// Define a function that modifies the upload directory
function custom_upload_dir( $params ) {
  // Get the current date
  $date = getdate();

  // Append the day to the subdirectory
  $params['subdir'] = $params['subdir'] . '/' . $date['mday'];

  // Update the path and url accordingly
  $params['path'] = $params['basedir'] . $params['subdir'];
  $params['url'] = $params['baseurl'] . $params['subdir'];

  // Return the modified parameters
  return $params;
}

// Add the filter to change the upload directory
add_filter( 'upload_dir', 'custom_upload_dir' );