Index: source/lobby/XmppClient.cpp
===================================================================
--- source/lobby/XmppClient.cpp
+++ source/lobby/XmppClient.cpp
@@ -936,8 +936,15 @@
 	if (!msg.when())
 		return std::time(nullptr);
 
-	// The locale is irrelevant, because the XMPP date format doesn't contain written month names
-	return g_L10n.ParseDateTime(msg.when()->stamp().to_string(), "Y-M-d'T'H:m:sZ", Locale::getUS()) / 1000.0;
+	// XEP-0082 allows timestamps with or without microseconds, so handle both
+	for (std::string format : {"Y-M-d'T'H:m:s.SZ", "Y-M-d'T'H:m:sZ"})
+        {
+		// The locale is irrelevant, because the XMPP date format doesn't contain written month names
+		UDate dateTime = g_L10n.ParseDateTime(msg.when()->stamp().to_string(), format, Locale::getUS());
+		if (dateTime)
+			return dateTime / 1000.0;
+	}
+	return std::time(nullptr);
 }
 
 /**