Get Calendar recurrent events by CSOM from SharePoint 2013.

gistfile1.txt

GetItemsFromCalendarAsmx = function (webUrl, calendarGuid) {

    wsURL = webUrl + "_vti_bin/Lists.asmx";

    var xmlCall =
        "<soap:Envelope xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xsd='http://www.w3.org/2001/XMLSchema' xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/'> <soap:Body>" +
        "<GetListItems xmlns='http://schemas.microsoft.com/sharepoint/soap/'>" +
        "<listName>" + calendarGuid + "</listName>" +
        "<query>" +
        "<Query>" +
        "<Where>" +
           "<DateRangesOverlap>" +
           "<FieldRef Name=\"EventDate\" />" +
           "<FieldRef Name=\"EndDate\" />" +
           "<FieldRef Name=\"RecurrenceID\" />" +
           "<Value Type='DateTime'><Year/></Value>" +
           "</DateRangesOverlap>" +
        "</Where>" +
        "</Query>" +
        "</query>" +
        "<queryOptions>" +
        "<QueryOptions>" +
            "<ExpandRecurrence>TRUE</ExpandRecurrence>" +
        "</QueryOptions>" +
        "</queryOptions>" +
        "</GetListItems>" +
        "</soap:Body></soap:Envelope>";
    var result = [];
    $.ajax({
        url: wsURL,
        type: "POST",
        dataType: "xml",
        async: false,
        data: xmlCall,
        complete: function (xData, status) {
            Core.LogMessage("Core.GetItemsFromCalendarAsmx-> url: " + wsURL + " status: " + status);
            if (status === "success") {
                var root = $(xData.responseText);
                root.find("listitems").children().children().each(function () {
                    $this = $(this);
                    var ids = $this.attr("ows_UniqueId").split(";");
                    var rec = $this.attr("ows_fRecurrence");
                    result.push({
                        "StartTime": $this.attr("ows_EventDate"),
                        "EndTime": $this.attr("ows_EndDate"),
                        "Title": $this.attr("ows_Title"),
                        "Recurrence": (rec === "1" ? true : false),
                        "Description": Core.HtmlDecode($this.attr("ows_Description")),
                        "Guid": ids[1],
                        "Id": ids[0],
                    });
                });
            }
        },
        contentType: "text/xml; charset=\"utf-8\""
    });
    return result;
};

I'm getting below error while executing above code - SharePoint Online! Any idea?
HTTP500: SERVER ERROR - The server encountered an unexpected condition that prevented it from fulfilling the request.
(XHR)POST - https://xxxx.sharepoint.com/_vti_bin/Lists.asmx
Please help