You may try to use OnAfterRenderView WebScheduler client side event in order to load editing form when WebScheduler is open. OnAfterRenderView is the client side event handler when calendar viewing is completed.

In this event, we’ll need to select cell first and then simply call ShowEditingForm() method. Example:

<script language="javascript" type="text/javascript">
    <!--
    function WebScheduler1_OnAfterRenderView(controlId, viewMode) {
        var WebScheduler1 = ISGetObject(controlId);
        var el = WebScheduler1.GetCellElement(new Date());

        WebScheduler1.ShowEditingForm("New", 0);

        return true;
    }
    -->
</script>