JS操作日期的工具类(获取本周、本月、本季度、本年、时间戳格式化

var now = new Date(); //当前日期
var nowDayOfWeek = now.getDay(); //今天本周的第几天
var nowDay = now.getDate(); //当前日
var nowMonth = now.getMonth(); //当前月
var nowYear = now.getYear(); //当前年
nowYear += (nowYear < 2000) ? 1900 : 0; //
 
var lastMonthDate = new Date(); //上月日期
lastMonthDate.setDate(1);
lastMonthDate.setMonth(lastMonthDate.getMonth()-1);
var lastYear = lastMonthDate.getYear();
var lastMonth = lastMonthDate.getMonth();
 
/*时间戳改日期--不传第二个参数返回年月日,传第二个参数返回年月日时分秒*/
function formatDateTime(inputTime, type) {
    var date = new Date(inputTime);
    var y = date.getFullYear();
    var m = date.getMonth() + 1;
    m = m < 10 ? ('0' + m) : m;
    var d = date.getDate();
    d = d < 10 ? ('0' + d) : d;
    var h = date.getHours();
    h = h < 10 ? ('0' + h) : h;
    var minute = date.getMinutes();
    var second = date.getSeconds();
    minute = minute < 10 ? ('0' + minute) : minute;
    second = second < 10 ? ('0' + second) : second;
    if(type) {
        return y + '-' + m + '-' + d+' '+h+':'+minute+':'+second;//2017-12-12 12:23:34    
    } else {
        return y + '-' + m + '-' + d; //2017-12-12
    }
}
 
 
//格局化日期：yyyy-MM-dd
function formatDate(date) {
    var myyear = date.getFullYear();
    var mymonth = date.getMonth()+1;
    var myweekday = date.getDate();
 
    if(mymonth < 10){
        mymonth = "0" + mymonth;
    }
    if(myweekday < 10){
        myweekday = "0" + myweekday;
    }
    return (myyear+"-"+mymonth + "-" + myweekday);
}
 
//获得某月的天数
function getMonthDays(myMonth){
    var monthStartDate = new Date(nowYear, myMonth, 1);
    var monthEndDate = new Date(nowYear, myMonth + 1, 1);
    var days = (monthEndDate - monthStartDate)/(1000 * 60 * 60 * 24);
    return days;
}
 
//获得本季度的开端月份
function getQuarterStartMonth(){
    var quarterStartMonth = 0;
    if(nowMonth<3){
        quarterStartMonth = 0;
    }
    if(2<nowMonth && nowMonth<6){
        quarterStartMonth = 3;
    }
    if(5<nowMonth && nowMonth<9){
        quarterStartMonth = 6;
    }
    if(nowMonth>8){
        quarterStartMonth = 9;
    }
    return quarterStartMonth;
}
 
//获得本周的开端日期
function getWeekStartDate() {
    var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek + 1);
    return formatDate(weekStartDate);
}
 
//获得本周的停止日期
function getWeekEndDate() {
    var weekEndDate = new Date(nowYear, nowMonth, nowDay + (7 - nowDayOfWeek));
    return formatDate(weekEndDate);
}
 
//获得本月的开端日期
function getMonthStartDate(){
    var monthStartDate = new Date(nowYear, nowMonth, 1);
    return formatDate(monthStartDate);
}
 
//获得本月的停止日期
function getMonthEndDate(){
    var monthEndDate = new Date(nowYear, nowMonth, getMonthDays(nowMonth));
    return formatDate(monthEndDate);
}
 
//获得上月开端时候
function getLastMonthStartDate(){
    var lastMonthStartDate = new Date(nowYear, lastMonth, 1);
    return formatDate(lastMonthStartDate);
}
 
//获得上月停止时候
function getLastMonthEndDate(){
    var lastMonthEndDate = new Date(nowYear, lastMonth, getMonthDays(lastMonth));
    return formatDate(lastMonthEndDate);
}
 
//获得本季度的开端日期
function getQuarterStartDate(){
 
    var quarterStartDate = new Date(nowYear, getQuarterStartMonth(), 1);
    return formatDate(quarterStartDate);
}
 
//或的本季度的停止日期
function getQuarterEndDate(){
    var quarterEndMonth = getQuarterStartMonth() + 2;
    var quarterStartDate = new Date(nowYear, quarterEndMonth, getMonthDays(quarterEndMonth));
    return formatDate(quarterStartDate);
}
 
// 获得本年开始日期
function getYearStartDate(){
    var yearStartDate = new Date(nowYear, 0, 1);
    return formatDate(yearStartDate);
}
// 获得本年结束日期
function getYearEndDate(){
    var yearEndDate = new Date(nowYear, 11, 1);
    return formatDate(yearEndDate);
}

来源：小流至江河
下面是我自己提取需要：

getTime() {
                
                var now = new Date(); //当前日期
                var nowDayOfWeek = now.getDay(); //今天本周的第几天
                var nowDay = now.getDate(); //当前日
                var nowMonth = now.getMonth(); //当前月
                var nowYear = now.getYear(); //当前年
                nowYear += (nowYear < 2000) ? 1900 : 0; //
                
                var lastMonthDate = new Date(); //上月日期
                lastMonthDate.setDate(1);
                lastMonthDate.setMonth(lastMonthDate.getMonth()-1);


                //获得某月的天数
                var monthStartDate = new Date(nowYear, nowMonth, 1);
                var monthEndDate = new Date(nowYear, nowMonth + 1, 1);
                var days = (monthEndDate - monthStartDate)/(1000 * 60 * 60 * 24);

                 // 本日开始
                const todayStartDate = new Date(new Date(new Date().toLocaleDateString())).getTime()
                // 本日结束
                const todayEndDate = new Date(new Date().toLocaleDateString()).getTime()+24*60*60*1000-1
                // 昨日开始
                const yesterdayStartDate = new Date(todayStartDate-24*60*60*1000+1).getTime()
                // 昨日结束
                const yesterdayEndDate = new Date(todayStartDate-1).getTime()
                // 获得本周的开端日期
                var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek + 1).getTime()
                //获得本周的停止日期
                var weekEndDate = new Date(nowYear, nowMonth, nowDay + (7 - nowDayOfWeek)).getTime()+24*60*60*1000-1
                //获得本月的开端日期
                var getMonthStartDate = new Date(nowYear, nowMonth, 1).getTime()
                //获得本月的停止日期
                var getMonthEndDate = new Date(nowYear, nowMonth, days).getTime()+24*60*60*1000-1
                console.log('本周的开端日期:',weekStartDate,'本周的停止日期:',weekEndDate,'本月的开端日期:',getMonthStartDate,'本月的停止日期:',getMonthEndDate)
                
                return {
                    todayStartDate: todayStartDate,
                    todayEndDate: todayEndDate,
                    yesterdayStartDate: yesterdayStartDate,
                    yesterdayEndDate: yesterdayEndDate,
                    weekStartDate: weekEndDate,
                    weekEndDate: weekEndDate,
                    getMonthStartDate: getMonthStartDate,
                    getMonthEndDate: getMonthEndDate
                }
                
            }