JavaScript版DateAdd和DateDiff函数代码

　　function DateAdd(interval,number,date){

　　switch(interval.toLowerCase()){

　　case "y": return new Date(date.setFullYear(date.getFullYear()+number));

　　case "m": return new Date(date.setMonth(date.getMonth()+number));

　　case "d": return new Date(date.setDate(date.getDate()+number));

　　case "w": return new Date(date.setDate(date.getDate()+7*number));

　　case "h": return new Date(date.setHours(date.getHours()+number));

　　case "n": return new Date(date.setMinutes(date.getMinutes()+number));

　　case "s": return new Date(date.setSeconds(date.getSeconds()+number));

　　case "l": return new Date(date.setMilliseconds(date.getMilliseconds()+number));

　　}

　　}

　　function DateDiff(interval,date1,date2){

　　var long = date2.getTime() - date1.getTime(); //相差毫秒

　　switch(interval.toLowerCase()){

　　case "y": return parseInt(date2.getFullYear() - date1.getFullYear());

　　case "m": return parseInt((date2.getFullYear() - date1.getFullYear())*12 + (date2.getMonth()-date1.getMonth()));

　　case "d": return parseInt(long/1000/60/60/24);

　　case "w": return parseInt(long/1000/60/60/24/7);

　　case "h": return parseInt(long/1000/60/60);

　　case "n": return parseInt(long/1000/60);

　　case "s": return parseInt(long/1000);

　　case "l": return parseInt(long);

　　}

　　}

　　<script type="text/javascript">

　　function NewDate(str) {

　　str = str.split('-');

　　var date = new Date();

　　date.setUTCFullYear(str[0], str[1] - 1, str[2]);

　　date.setUTCHours(0, 0, 0, 0);

　　return date;

　　}

　　function TimeCom(dateValue) {

　　var newCom;

　　if (dateValue == "") {

　　newCom = new Date();

　　} else {

　　newCom = NewDate(dateValue);

　　}

　　this.year = newCom.getYear();

　　this.month = newCom.getMonth() + 1;

　　this.day = newCom.getDate();

　　this.hour = newCom.getHours();

　　this.minute = newCom.getMinutes();

　　this.second = newCom.getSeconds();

　　this.msecond = newCom.getMilliseconds();

　　this.week = newCom.getDay();

　　}

　　function DateDiff(interval, date1, date2) {

　　var TimeCom1 = new TimeCom(date1);

　　var TimeCom2 = new TimeCom(date2);

　　var result;

　　switch (String(interval).toLowerCase()) {

　　case "y":

　　case "year":

　　result = TimeCom1.year - TimeCom2.year;

　　break;

　　case "m":

　　case "month":

　　result = (TimeCom1.year - TimeCom2.year) * 12 + (TimeCom1.month - TimeCom2.month);

　　break;

　　case "d":

　　case "day":

　　result = Math.round((Date.UTC(TimeCom1.year, TimeCom1.month - 1, TimeCom1.day) - Date.UTC(TimeCom2.year, TimeCom2.month - 1, TimeCom2.day)) / (1000 * 60 * 60 * 24));

　　break;

　　case "h":

　　case "hour":

　　result = Math.round((Date.UTC(TimeCom1.year, TimeCom1.month - 1, TimeCom1.day, TimeCom1.hour) - Date.UTC(TimeCom2.year, TimeCom2.month - 1, TimeCom2.day, TimeCom2.hour)) / (1000 * 60 * 60));

　　break;

　　case "min":

　　case "minute":

　　result = Math.round((Date.UTC(TimeCom1.year, TimeCom1.month - 1, TimeCom1.day, TimeCom1.hour, TimeCom1.minute) - Date.UTC(TimeCom2.year, TimeCom2.month - 1, TimeCom2.day, TimeCom2.hour, TimeCom2.minute)) / (1000 * 60));

　　break;

　　case "s":

　　case "second":

　　result = Math.round((Date.UTC(TimeCom1.year, TimeCom1.month - 1, TimeCom1.day, TimeCom1.hour, TimeCom1.minute, TimeCom1.second) - Date.UTC(TimeCom2.year, TimeCom2.month - 1, TimeCom2.day, TimeCom2.hour, TimeCom2.minute, TimeCom2.second)) / 1000);

　　break;

　　case "ms":

　　case "msecond":

　　result = Date.UTC(TimeCom1.year, TimeCom1.month - 1, TimeCom1.day, TimeCom1.hour, TimeCom1.minute, TimeCom1.second, TimeCom1.msecond) - Date.UTC(TimeCom2.year, TimeCom2.month - 1, TimeCom2.day, TimeCom2.hour, TimeCom2.minute, TimeCom2.second, TimeCom1.msecond);

　　break;

　　case "w":

　　case "week":

　　result = Math.round((Date.UTC(TimeCom1.year, TimeCom1.month - 1, TimeCom1.day) - Date.UTC(TimeCom2.year, TimeCom2.month - 1, TimeCom2.day)) / (1000 * 60 * 60 * 24)) % 7;

　　break;

　　default:

　　result = "invalid";

　　}

　　return (result);

　　}

　　</script>