Jquery: Validate multiple checkbox with jquery unobtrusive

i have many checkboxes and i want user has to select one. if none selected then validation message will be selected. here is my code but validation message is not showing.

checkbox html

<div class="col-md-offset-2 col-md-10">
<b>Hobbies</b><br>
<input type="checkbox" value="true" name="Hobbies[0].IsSelected" id="Hobbies_0__IsSelected" data-val-required="The IsSelected field is required." data-val="true" class="hobbycls input-validation-error"><input type="hidden" value="false" name="Hobbies[0].IsSelected">  &nbsp; 
<label for="Hobbies_0__IsSelected">Reading</label>  &nbsp;
<input type="hidden" value="Reading" name="Hobbies[0].Name" id="Hobbies_0__Name"><input type="checkbox" value="true" name="Hobbies[1].IsSelected" id="Hobbies_1__IsSelected" data-val-required="The IsSelected field is required." data-val="true" class="hobbycls input-validation-error"><input type="hidden" value="false" name="Hobbies[1].IsSelected">  &nbsp; 
<label for="Hobbies_1__IsSelected">Sports</label>  &nbsp;
<input type="hidden" value="Sports" name="Hobbies[1].Name" id="Hobbies_1__Name"><input type="checkbox" value="true" name="Hobbies[2].IsSelected" id="Hobbies_2__IsSelected" data-val-required="The IsSelected field is required." data-val="true" class="hobbycls input-validation-error"><input type="hidden" value="false" name="Hobbies[2].IsSelected">  &nbsp; 
<label for="Hobbies_2__IsSelected">Movies</label>  &nbsp;
<input type="hidden" value="Movies" name="Hobbies[2].Name" id="Hobbies_2__Name">                <span data-valmsg-replace="true" data-valmsg-for="Hobbies" class="field-validation-valid"></span>

jquery unobtrusive validation code

$(function () {
    $.validator.addMethod("CheckOneCategory", function (value, element) {

        //var tag = $(".col-md-offset-2 col-md-10").find(":checkbox");
        //alert(tag.filter(':checked').length);
        //return tag.filter(':checked').length;
        if ($(".hobbycls:checkbox:checked").length > 0) {
            return true;
        } else {
            alert('hello');
            return false;
        }

    }, "Select at least one hobby");
    $.validator.addClassRules("hobbycls", { CheckOneCategory: true });
});