获取当天过去每半小时的时间

function formatTodayHalfHours(nowDate = +new Date()) { 
    var timeStamp = new Date(new Date().setHours(0, 0, 0, 0));
    var dateList = []; 

    while (nowDate > timeStamp) {
        var hour = new Date(nowDate).getHours() < 10 ? '0' + new Date(nowDate).getHours() : new Date(nowDate).getHours();
        var minute = new Date(nowDate).getMinutes() < 31 ? '00' : '30';
        dateList.unshift(hour + ':' + minute + ':' + '00'); 
        nowDate -= 30 * 60 * 1000
    }
    return dateList
}