I used scheduler version 4 professional and i set in the document head
<script src="/static/dhtmlx/dhtmlxScheduler/sources/locale/locale_de.js" charset="utf-8" type="text/javascript"></script>
<script src="/static/dhtmlx/dhtmlxScheduler/sources/locale/recurring/locale_recurring_de.js" charset="utf-8" type="text/javascript"></script>
but nothing change.
The Demo Page schould be espanol, but ist english too.
http://docs.dhtmlx.com/scheduler/samples/01_initialization_loading/07_locale_usage.html
Its a bug?