JS函数 计算 今日，昨日，本周，上周，本月

最近有个功能会进行数据的筛选于是便写了几个快速计算 今日，昨日，本周，上周，本月 范围的function 以便以后遇到同样的问题可以直接进行复用，代码如下：

/*
*获取今日的起始和结束时间
*返回值："起始时间,结束时间"
*/
function ToDayStr() {
    var returnStr = "";
    var date = new Date();      //当前时间
    var year = date.getFullYear();
    var month = date.getMonth() + 1;
    var day = date.getDate();
    //var hour = date.getHours();
    //var minutes = date.getMinutes();
    //var second = date.getSeconds();
    month = month < 10 ? "0" + month : month;
    day = day < 10 ? "0" + day : day;
    returnStr = year + "/" + month + "/" + day + " 00:00:00,";       //起始时间
    returnStr += year + "/" + month + "/" + day + " 23:59:59";      //结束时间
    return returnStr;
}

/*
*获取昨日的起始和结束时间
*返回值："起始时间,结束时间"
*/
function YesterDayStr() {
    var date = GetDate(1, 1);       //当前时间前一天
    var returnStr = "";
    var year = date.getFullYear();
    var month = date.getMonth() + 1;
    var day = date.getDate();
    month = month < 10 ? "0" + month : month;
    day = day < 10 ? "0" + day : day;
    returnStr = year + "/" + month + "/" + day + " 00:00:00,";       //起始时间
    returnStr += year + "/" + month + "/" + day + " 23:59:59";      //结束时间
    return returnStr;
}

/*
*获取本周的起始和结束时间
*返回值："起始时间,结束时间"
*/
function ThisWeekStr() {
    var returnStr = "";
    var date = new Date();      //当前时间
    var week = date.getDay();   //获取今天星期几
    var monday = GetDate2(week - 1, 1, date);      //获取星期一
    var sunday = GetDate2(7 - week, 2, date);   //获取星期天
    //起始时间的年月日
    var year1 = monday.getFullYear();
    var month1 = monday.getMonth() + 1;
    var day1 = monday.getDate();
    //结束时间的年月日
    var year2 = sunday.getFullYear();
    var month2 = sunday.getMonth() + 1;
    var day2 = sunday.getDate();
    //处理起始时间小于10的追加"0"在前面
    month1 = month1 < 10 ? "0" + month1 : month1;
    day1 = day1 < 10 ? "0" + day1 : day1;
    //处理结束时间小于10的追加"0"在前面
    month2 = month2 < 10 ? "0" + month2 : month2;
    day2 = day2 < 10 ? "0" + day2 : day2;

    returnStr = year1 + "/" + month1 + "/" + day1 + " 00:00:00,";       //起始时间
    returnStr += year2 + "/" + month2 + "/" + day2 + " 23:59:59";      //结束时间
    return returnStr;
}

/*
*获取上周的起始和结束时间
*返回值："起始时间,结束时间"
*/
function LastWeekStr() {
    var returnStr = "";
    var date = new Date();      //当前时间
    var week = date.getDay();   //获取今天星期几
    var monday = GetDate2(week + 6, 1, date);      //获取上周星期一
    var sunday = GetDate2(week, 1, date);          //获取上周星期天
    //起始时间的年月日
    var year1 = monday.getFullYear();
    var month1 = monday.getMonth() + 1;
    var day1 = monday.getDate();
    //结束时间的年月日
    var year2 = sunday.getFullYear();
    var month2 = sunday.getMonth() + 1;
    var day2 = sunday.getDate();
    //处理起始时间小于10的追加"0"在前面
    month1 = month1 < 10 ? "0" + month1 : month1;
    day1 = day1 < 10 ? "0" + day1 : day1;
    //处理结束时间小于10的追加"0"在前面
    month2 = month2 < 10 ? "0" + month2 : month2;
    day2 = day2 < 10 ? "0" + day2 : day2;

    returnStr = year1 + "/" + month1 + "/" + day1 + " 00:00:00,";       //起始时间
    returnStr += year2 + "/" + month2 + "/" + day2 + " 23:59:59";      //结束时间
    return returnStr;
}

/*
*获取本月的起始和结束时间
*返回值："起始时间,结束时间"
*/
function ThisMonthStr() {
    var returnStr = "";
    var date = new Date();      //当前时间
    var year = date.getFullYear();
    var month = date.getMonth();

    var min = new Date(year, month, 1);                 //本月月初
    var max = new Date(year, month + 1, 0);             //本月月底

    //起始时间的年月日
    var year1 = min.getFullYear();
    var month1 = min.getMonth() + 1;
    var day1 = min.getDate();
    //结束时间的年月日
    var year2 = max.getFullYear();
    var month2 = max.getMonth() + 1;
    var day2 = max.getDate();
    //处理起始时间小于10的追加"0"在前面
    month1 = month1 < 10 ? "0" + month1 : month1;
    day1 = day1 < 10 ? "0" + day1 : day1;
    //处理结束时间小于10的追加"0"在前面
    month2 = month2 < 10 ? "0" + month2 : month2;
    day2 = day2 < 10 ? "0" + day2 : day2;

    returnStr = year1 + "/" + month1 + "/" + day1 + " 00:00:00,";       //起始时间
    returnStr += year2 + "/" + month2 + "/" + day2 + " 23:59:59";      //结束时间
    return returnStr;
}

/*
*获取当前日期前N天或后N日期(N = day)
*type:1：前；2：后
*/
function GetDate(day, type) {
    var zdate = new Date();
    var edate;
    if (type === 1) {
        edate = new Date(zdate.getTime() - (day * 24 * 60 * 60 * 1000));
    } else {
        edate = new Date(zdate.getTime() + (day * 24 * 60 * 60 * 1000));
    }
    return edate;
}

/*
*获取传入的日期前N天或后N日期(N = day)
*type:1：前；2：后
*date：传入的日期
*/
function GetDate2(day, type, date) {
    var zdate;
    if (date === null || date === undefined) {
        zdate = new Date();
    } else {
        zdate = date;
    }
    var edate;
    if (type === 1) {
        edate = new Date(zdate.getTime() - (day * 24 * 60 * 60 * 1000));
    } else {
        edate = new Date(zdate.getTime() + (day * 24 * 60 * 60 * 1000));
    }
    return edate;
}

　这里面需要注意的是不要单纯的在日期或时间上进行加减，注意日期的前后通常处理的都是毫秒数 ，可仿照以上代码中的GetDate 函数思路，仅供参考，如有疑问欢迎大家留言进行交流