diff --git a/src/SemanticScuttle/Service/Bookmark.php b/src/SemanticScuttle/Service/Bookmark.php
index 13153503..91d0c182 100644
--- a/src/SemanticScuttle/Service/Bookmark.php
+++ b/src/SemanticScuttle/Service/Bookmark.php
@@ -699,7 +699,7 @@ public function updateBookmark(
      * @param integer $enddate   Filter for creation date.
      *                           SQL-DateTime value
      *                           "YYYY-MM-DD hh:ii:ss'
-     * @param string  $hash      Filter by URL hash
+     * @param mixed   $hash      Filter by URL hash, may be an array of hashes or a single hash string
      *
      * @return array Array with two keys: 'bookmarks' and 'total'.
      *               First contains an array of bookmarks, 'total'
@@ -896,7 +896,14 @@ public function getBookmarks(
 
         // Hash
         if ($hash) {
-            $query_4 .= ' AND B.bHash = "'. $hash .'"';
+            if (!is_array($hash)) {
+                $hash = array($hash);
+            }
+            $hash_query = array();
+            foreach ($hash as $h) {
+                $hash_query[] = ' B.bHash = "'. $h .'" ';
+            }
+            $query_4 .= ' AND ('. implode($hash_query, ' OR ') .') ';
         }
 
 
diff --git a/www/api/posts_add.php b/www/api/posts_add.php
index 80d65155..121325f8 100644
--- a/www/api/posts_add.php
+++ b/www/api/posts_add.php
@@ -6,8 +6,8 @@
  * @param string  $url         URL of the bookmark (required)
  * @param string  $description Bookmark title (required)
  * @param string  $extended    Extended bookmark description (optional)
- * @param string  $tags        Space-separated list of tags (optional)
- * @param string  $dt          Date and time of bookmark creation (optional)
+ * @param string  $tags        comma delimited list of tags (optional)
+ * @param string  $dt          UTC Date and time of bookmark creation (optional)
  *                             Must be of format YYYY-MM-DDTHH:II:SSZ
  * @param integer $status      Visibility status (optional):
  *                             - 2 or 'private': Bookmark is totally private
@@ -20,7 +20,6 @@
  *                             same URL (optional)
  *
  * Notes:
- * - tags cannot have spaces
  * - URL and description (title) are mandatory
  * - delicious "description" is the "title" in SemanticScuttle
  * - delicious "extended" is the "description" in SemanticScuttle
@@ -74,7 +73,8 @@
 }
 
 if (isset($_REQUEST['dt']) && (trim($_REQUEST['dt']) != '')) {
-    $dt = trim($_REQUEST['dt']);
+    $date = new DateTime( trim($_REQUEST['dt']) , new DateTimeZone('UTC')); //adjust to UTC
+    $dt = date('Y-m-d\TH:i:s\Z', $date->getTimestamp());
 } else {
     $dt = null;
 }
@@ -134,7 +134,7 @@
 
     if (!$exists) {
         $added = $bs->addBookmark(
-            $url, $description, $extended, '', $status, $tags, null, $dt, true
+            $url, $description, $extended, '', $status, $tags, null, $dt, false //false, because new API uses comma separated tags
         );
         $msg = 'done';
     }
@@ -143,4 +143,4 @@
 // Set up the XML file and output the result.
 echo '<?xml version="1.0" standalone="yes" ?' . ">\r\n";
 echo '<result code="' . $msg .'" />';
-?>
\ No newline at end of file
+?>
diff --git a/www/api/posts_all.php b/www/api/posts_all.php
index c70d14c4..eff53496 100644
--- a/www/api/posts_all.php
+++ b/www/api/posts_all.php
@@ -1,19 +1,62 @@
 <?php
-// Implements the del.icio.us API request for all a user's posts, optionally filtered by tag.
+// Implements the del.icio.us API request for all a user's posts.
 
-// del.icio.us behavior:
-// - doesn't include the filtered tag as an attribute on the root element (we do)
+// Arguments: (copied from: https://github.com/SciDevs/delicious-api/blob/master/api/posts.md#v1postsallhashes on 2014-05-18)
+/*
+- `&tag_separator=comma` (optional) - (Recommended) Returns tags separated by a comma, instead of a space character. A space separator is currently used by default to avoid breaking existing clients - these default may change in future API revisions.
+- `&tag={TAG}` (optional) — Filter by this tag.
+- `&start={xx}` (optional) — Start returning posts this many results into the set.
+- `&results={xx}` (optional) — Return up to this many results. By default, up to 1000 bookmarks are returned. (no limits in scuttles)
+- `&fromdt={CCYY-MM-DDThh:mm:ssZ}` (optional) — Filter for posts on this date or later.
+- `&todt={CCYY-MM-DDThh:mm:ssZ}` (optional) — Filter for posts on this date or earlier.
+- `&meta=yes` (optional) — Include change detection signatures on each item in a ‘meta’ attribute. Clients wishing to maintain a synchronized local store of bookmarks should retain the value of this attribute - its value will change when any significant field of the bookmark changes.
+*/
 
 // Scuttle behavior:
 // - returns privacy status of each bookmark.
+// - There is no upper limit for the 'results' argument
+
+// fail, will be called, if somethink "goes wrong" to copy delicious behaviour
+function fail() {
+    echo '<result code="something went wrong"/>';
+    exit();
+}
+
+// no_bookmarks: indicate, that there are no bookmarks using these filters
+function no_bookmarks() {
+    echo '<result code="no bookmarks"/>';
+    exit();
+}
 
 // Force HTTP authentication first!
 $httpContentType = 'text/xml';
 require_once 'httpauth.inc.php';
 
+// xml header
+echo '<?xml version="1.0" encoding="UTF-8" ?'.">\r\n";
+
 /* Service creation: only useful services are created */
 $bookmarkservice =SemanticScuttle_Service_Factory::get('Bookmark');
 
+// special case - hashes: only return url hash and meta (change indicator)
+if ( isset($_REQUEST['hashes']) ) {
+    // get all bookmarks
+    $bookmarks = $bookmarkservice->getBookmarks(0, NULL, $userservice->getCurrentUserId());
+
+    // output:
+    // Set up the XML file and output all the posts.
+    echo "<posts>\r\n";
+    foreach($bookmarks['bookmarks'] as $row) {
+        $url = md5($row['bAddress']);
+        //create a meta, which changes, when the bookmark changes in the form of a md5 hash (as delicious does it).
+        $meta = md5($row['bModified']);
+
+        echo "\t<post meta=\"". $meta .'" url="'. $url ."\"/>\r\n";
+    }
+
+    echo '</posts>';
+    exit();
+}
 
 // Check to see if a tag was specified.
 if (isset($_REQUEST['tag']) && (trim($_REQUEST['tag']) != ''))
@@ -21,12 +64,63 @@
 else
     $tag = NULL;
 
+// 'tag separator' option
+if (isset($_REQUEST['tag_separator']) && (trim($_REQUEST['tag_separator']) == 'comma')) 
+    $tag_separator = ',';
+else
+    $tag_separator = ' ';
+
+// 'start' option
+if (isset($_REQUEST['start']) && (intval($_REQUEST['start']) > 0))
+    $start = intval($_REQUEST['start']);
+else
+    $start = 0; //default in delicious api
+
+// 'results' option
+// upper limit of delicious api is 100000. There is no upper limit here. TODO: implement upper limit?
+if (isset($_REQUEST['results'])) {
+    if( $_REQUEST['results'] < 0 )
+        fail(); //like delicious
+    elseif( $_REQUEST['results'] == 0 )
+        no_bookmarks();
+    else
+        $results = intval($_REQUEST['results']);
+} else {
+    $results = 1000; //default, as in delicious api
+}
+
+// 'fromdt' option: filter result by date
+if (isset($_REQUEST['fromdt'])) {
+    $date = new DateTime( $_REQUEST['fromdt'] , new DateTimeZone('UTC')); //adjust to UTC
+    $fromdt = date('Y-m-d\TH:i:s\Z', $date->getTimestamp());
+} else {
+    $fromdt = NULL;
+}
+
+// 'todt' option: filter result by date
+if (isset($_REQUEST['todt'])) {
+    $date = new DateTime( $_REQUEST['todt'] , new DateTimeZone('UTC')); //adjust to UTC
+    $todt = date('Y-m-d\TH:i:s\Z', $date->getTimestamp());
+} else {
+    $todt = NULL;
+}
+
+// 'meta' option: get meta (change indicator)
+if (isset($_REQUEST['meta']) && (trim($_REQUEST['meta']) == 'yes'))
+    $meta = true;
+else
+    $meta = false;
+
 // Get the posts relevant to the passed-in variables.
-$bookmarks = $bookmarkservice->getBookmarks(0, NULL, $userservice->getCurrentUserId(), $tag);
+$bookmarks = $bookmarkservice->getBookmarks($start, $results, $userservice->getCurrentUserId(), $tag, NULL, NULL, NULL, $fromdt, $todt);
+
+// check for empty result
+if (count($bookmarks['bookmarks'])==0) {
+    no_bookmarks();
+}
 
 // Set up the XML file and output all the posts.
-echo '<?xml version="1.0" standalone="yes" ?'.">\r\n";
-echo '<posts update="'. gmdate('Y-m-d\TH:i:s\Z') .'" user="'. htmlspecialchars($currentUser->getUsername()) .'"'. (is_null($tag) ? '' : ' tag="'. htmlspecialchars($tag) .'"') .">\r\n";
+echo '<posts update="'. gmdate('Y-m-d\TH:i:s\Z') .'" user="'. htmlspecialchars($currentUser->getUsername()) .'" total="'. count($bookmarks['bookmarks']) .'" '. (is_null($tag) ? '' : ' tag="'. htmlspecialchars($tag) .'"') .">\r\n";
 
 foreach($bookmarks['bookmarks'] as $row) {
     if (is_null($row['bDescription']) || (trim($row['bDescription']) == ''))
@@ -37,13 +131,19 @@
     $taglist = '';
     if (count($row['tags']) > 0) {
         foreach($row['tags'] as $tag)
-            $taglist .= convertTag($tag) .' ';
+            $taglist .= convertTag($tag) . $tag_separator;
         $taglist = substr($taglist, 0, -1);
     } else {
         $taglist = 'system:unfiled';
     }
 
-    echo "\t<post href=\"". filter($row['bAddress'], 'xml') .'" description="'. filter($row['bTitle'], 'xml') .'" '. $description .'hash="'. md5($row['bAddress']) .'" tag="'. filter($taglist, 'xml') .'" time="'. gmdate('Y-m-d\TH:i:s\Z', strtotime($row['bDatetime'])) . '" status="'. filter($row['bStatus'], 'xml') ."\" />\r\n";
+    if( $meta ) {
+        $meta_print = ' meta="'. md5($row['bModified']) .'" ';
+    } else {
+        $meta_print = '';
+    }
+
+    echo "\t<post href=\"". filter($row['bAddress'], 'xml') .'" description="'. filter($row['bTitle'], 'xml') .'" '. $description .'hash="'. md5($row['bAddress']) .'" tag="'. filter($taglist, 'xml') .'" time="'. gmdate('Y-m-d\TH:i:s\Z', strtotime($row['bDatetime'])) . '"  '. $meta_print .' status="'. filter($row['bStatus'], 'xml') ."\" />\r\n";
 }
 
 echo '</posts>';
diff --git a/www/api/posts_get.php b/www/api/posts_get.php
index e39058b5..fa16b868 100644
--- a/www/api/posts_get.php
+++ b/www/api/posts_get.php
@@ -32,32 +32,70 @@
 /* Service creation: only useful services are created */
 $bookmarkservice = SemanticScuttle_Service_Factory::get('Bookmark');
 
+//// 'meta' argument
+$includeMeta = (isset($_REQUEST['meta']) && (trim($_REQUEST['meta']) == 'yes'));
 
-// Check to see if a tag was specified.
-if (isset($_REQUEST['tag']) && (trim($_REQUEST['tag']) != '')) {
-    $tag = trim($_REQUEST['tag']);
+//// 'tag_separator' argument
+if (isset($_REQUEST['tag_separator']) && (trim($_REQUEST['tag_separator']) == 'comma')) {
+    $tag_separator = ',';
 } else {
-    $tag = null;
+    $tag_separator = ' ';
 }
 
-// Check to see if a date was specified; the format should be YYYY-MM-DD
-if (isset($_REQUEST['dt']) && (trim($_REQUEST['dt']) != '')) {
-    $dtstart = trim($_REQUEST['dt']);
-} else {
-    $dtstart = date('Y-m-d H:i:s');
+//// 'url' argument
+if (isset($_REQUEST['url']) && (trim($_REQUEST['url']) != '')) {
+    $_REQUEST['hashes'] = md5($_REQUEST['url']);
 }
-$dtend = date('Y-m-d H:i:s', strtotime($dtstart .'+1 day'));
 
-// Get the posts relevant to the passed-in variables.
-$bookmarks = $bookmarkservice->getBookmarks(
-    0, null, $userservice->getCurrentUserId(), $tag,
-    null, null, null, $dtstart, $dtend
-);
+//// 'hashes' argument
+if (isset($_REQUEST['hashes']) && (trim($_REQUEST['hashes']) != '')) {
+    $hashes = explode(' ', trim($_REQUEST['hashes']) );
+    // directly get the bookmarks for these hashes
+    //TODO: getBookmarks can't handle multiple hashes
+    $bookmarks = $bookmarkservice->getBookmarks(
+        0, null, $userservice->getCurrentUserId(), null,
+        null, null, null, null, null, $hashes
+    );
+} else {
+
+    //// 'tag' argument
+    // Check to see if a tag was specified.
+    if (isset($_REQUEST['tag']) && (trim($_REQUEST['tag']) != '')) {
+        // convert spaces back to '+' and explode
+        $tag = str_replace(' ', '+', trim($_REQUEST['tag']));
+        $tag = explode('+', $tag);
+    } else {
+        $tag = null;
+    }
+
+    //// 'dt' argument
+    // Check to see if a date was specified; the format should be YYYY-MM-DD in GMT/UTC
+    if (isset($_REQUEST['dt']) && (trim($_REQUEST['dt']) != '')) {
+        $dtstart = trim($_REQUEST['dt']);
+    } else {
+        $dtstart = gmdate('Y-m-d') . ' 00:00:00'; //Default: Today midnight (UTC)
+    }
+    //adjust from UTC to server time
+    $date = new DateTime( $dtstart , new DateTimeZone('UTC'));
+    $dtstart = date('Y-m-d H:i:s', $date->getTimestamp());
+    $dtstart_day = date('Y-m-d', $date->getTimestamp());
+
+    $dtend = date('Y-m-d H:i:s', strtotime($dtstart .'+1 day'));
+
+    //
+
+    // Get the posts relevant to the passed-in variables.
+    $bookmarks = $bookmarkservice->getBookmarks(
+        0, null, $userservice->getCurrentUserId(), $tag,
+        null, null, null, $dtstart, $dtend
+    );
+
+}
 
 
 // Set up the XML file and output all the tags.
-echo '<?xml version="1.0" standalone="yes" ?'.">\r\n";
-echo '<posts'. (is_null($dtstart) ? '' : ' dt="'. $dtstart .'"') .' tag="'. (is_null($tag) ? '' : filter($tag, 'xml')) .'" user="'. filter($currentUser->getUsername(), 'xml') ."\">\r\n";
+echo '<?xml version="1.0" encoding="UTF-8" ?'.">\r\n";
+echo '<posts'. (is_null($dtstart_day) ? '' : ' dt="'. $dtstart_day .'"') .' tags="'. (is_null($tag) ? '' : filter(implode($tag, $tag_separator), 'xml')) .'" user="'. filter($currentUser->getUsername(), 'xml') ."\">\r\n";
 
 foreach ($bookmarks['bookmarks'] as $row) {
     if (is_null($row['bDescription']) || (trim($row['bDescription']) == '')) {
@@ -69,14 +107,14 @@
     $taglist = '';
     if (count($row['tags']) > 0) {
         foreach ($row['tags'] as $tag) {
-            $taglist .= convertTag($tag) . ' ';
+            $taglist .= convertTag($tag) . $tag_separator;
         }
         $taglist = substr($taglist, 0, -1);
     } else {
         $taglist = 'system:unfiled';
     }
 
-    echo "\t<post href=\"". filter($row['bAddress'], 'xml') .'" description="'. filter($row['bTitle'], 'xml') .'" '. $description .'hash="'. $row['bHash'] .'" others="'. $bookmarkservice->countOthers($row['bAddress']) .'" tag="'. filter($taglist, 'xml') .'" time="'. gmdate('Y-m-d\TH:i:s\Z', strtotime($row['bDatetime'])) . '" status="'. filter($row['bStatus'], 'xml') ."\" />\r\n";
+    echo "\t<post href=\"". filter($row['bAddress'], 'xml') .'" description="'. filter($row['bTitle'], 'xml') .'" '. $description .'hash="'. $row['bHash'] .'" '. ($includeMeta?'meta="'. md5($row['bModified']) .'"':'') .' others="'. $bookmarkservice->countOthers($row['bAddress']) .'" tag="'. filter($taglist, 'xml') .'" time="'. gmdate('Y-m-d\TH:i:s\Z', strtotime($row['bDatetime'])) . '" private="'. ($row['bStatus']==2?'yes':'no') .'" shared="'. ($row['bStatus']==2?'no':'yes') .'" status="'. filter($row['bStatus'], 'xml') ."\" />\r\n";
 }
 
 echo '</posts>';