It would be helpful to have a way to set the major tick step value via the RadHtmlChart control. This can be set on the client side, but it seems like a missing feature since I can change the major tick size and label step values via the control axis attributes. Here's an example with my suggested attribute shown in comments on the xAxis below.
<telerik:RadHtmlChart runat="server" ID="RadHtmlChart1" DataSourceID="RequestDays">
<ClientEvents OnLoad="OnLoad" />
<PlotArea>
<Series>
<telerik:AreaSeries Name="Last Year" DataFieldY="Last"></telerik:AreaSeries>
<telerik:AreaSeries Name="Current Year" DataFieldY="Current"></telerik:AreaSeries>
</Series>
<XAxis Name="Days" DataLabelsField="Days" MajorTickSize="5"> <%--MajorTickStep="7"--%>
<LabelsAppearance Step="14" />
</XAxis>
</PlotArea>
</telerik:RadHtmlChart>
<script type="text/javascript">
function OnLoad(chart) {
var widget = chart.get_kendoWidget();
widget.options.categoryAxis.majorTicks = { step: 7 };
widget.redraw();
}
</script>