How to get the current quarter, according to the current month with javascript

function getQuarterByMonth(){
    var today = new Date(); //获取当前时间
    var month = today.getMonth() + 1;//getMonth返回0-11
    //下面是几个if
    if(month >=1 && month <=3){
    	return 1;
    }else if(month >=4 && month <=6){
        return 2;
    }else if(month >=7 && month <=9){
        return 3;
    }else{
        return 4;
    }    
}