How to automatically set Date on http header in jquery, manually set header sends me a Refused to set unsafe header "Date" error

I am using the HMAC for authentication, but

 $.ajax({
            type: "POST",
            url: baseURL + "/test/hmac",
            contentType: "application/json",
            dataType: "json",
            beforeSend: function (request) {                    
                request.setRequestHeader('authorization', 'AuthHMAC '+client.key +":" + CryptoJS.HmacSHA1(canonical_string, client.secret).toString(CryptoJS.enc.Base64));
                request.setRequestHeader('content-md5', md5);
                request.setRequestHeader('Dates', date);         //Refused to set unsafe header "Date"      
            },    
            data: JSON.stringify(data),
            success: function (data) {
                alert(data.message);
            },
            error: function (errorMessage) {
               if(errorMessage.status == 401)
                   alert('Access denied');
            }
        });

however the code gets a error on request.setRequestHeader('Date', date); that the browser says to me 'Refused to set unsafe header "Date" '

this is problematic since Date header is important for HMAC against replay attack, so as I can't change much on the server , how can I do it on the client side to let it automatically add Date to the header