JS中new Date().Format(＂YYYY-mm-dd＂)提示Format is not a function的解决办法

idp.event.bind("loadData", function() {

    let CURRENT_ELECATION_DATE = idp.control.get('CURRENT_ELECATION_DATE').getValue();
    if (CURRENT_ELECATION_DATE == null) {

    } else {

        var date = new Date(CURRENT_ELECATION_DATE);
        console.log(date);

        date.setFullYear(date.getFullYear() + 3);
        date.setDate(date.getDate() - 1);
        console.log(new Date().toLocaleDateString().split('/').join('-'));

        idp.control.get('GENERAL_ELECATION_DATE').setValue(date.toLocaleDateString().split('/').join('-'));


    }
});

const date = new Date();
date.toLocaleString('zh', { hour12: true });  //2018/4/4 下午6:57:36
date.toLocaleString('zh', { hour24: false });  //2018/4/4 18:57:36
hour12 表示的是使用十二小时制还是使用二十四小时制，默认值是十二小时制。看栗子