When were Confluence Spaces last modified? Use the Confluence REST API to get all Spaces and the date of the latest content change in each.

spaces.php

<?php

define('BASE', 'https://wiki.domain.com/rest/api/');
define('USERNAME' , 'foo');
define('PASSWORD' , 'bar');

function prepareCall(&$curl, $query) {
    curl_setopt($curl, CURLOPT_URL, BASE . $query);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_USERPWD, USERNAME . ':' . PASSWORD);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 0);
}

function getAllSpaces() {
    $ch = curl_init();
    prepareCall($ch, 'space?expand=metadata&limit=500');
    $result = curl_exec($ch);

    return $result;
}

function getSpaceDetails($space){
    $ch = curl_init();
    prepareCall($ch, 'content/search?cql=space%3D' . $space. '%20and%20type%3Dpage%20order%20by%20lastmodified%20desc&expand=version&limit=1');
    $result = curl_exec($ch);

    return $result;
}

$spaces = json_decode(getAllSpaces());

echo "space;lastModified;\n";

foreach ($spaces->results as $_space) {
    $_spaceDetails = json_decode(getSpaceDetails($_space->key));
    $_spaces[$_space->key] =  $_spaceDetails->results[0]->version->when;

    echo $_space->key . ';' . date("d.m.Y", strtotime($_spaceDetails->results[0]->version->when)) . ";\n";
}

?>