Js获取当前日期时间及其它操作

var myDate = new Date();
myDate.getYear();        //获取当前年份(2位)
myDate.getFullYear();    //获取完整的年份(4位,1970-????)
myDate.getMonth();       //获取当前月份(0-11,0代表1月)
myDate.getDate();        //获取当前日(1-31)
myDate.getDay();         //获取当前星期X(0-6,0代表星期天)
myDate.getTime();        //获取当前时间(从1970.1.1开始的毫秒数)
myDate.getHours();       //获取当前小时数(0-23)
myDate.getMinutes();     //获取当前分钟数(0-59)
myDate.getSeconds();     //获取当前秒数(0-59)
myDate.getMilliseconds();    //获取当前毫秒数(0-999)
myDate.toLocaleDateString();     //获取当前日期
var mytime=myDate.toLocaleTimeString();     //获取当前时间
myDate.toLocaleString( );        //获取日期与时间

//获得 yyyy-mm-dd HH-mm-ss模式
Date.prototype.Format = function (fmt) { //author: meizz 
    var o = {
        "M+": this.getMonth() + 1, //月份 
        "d+": this.getDate(), //日 
        "h+": this.getHours(), //小时 
        "m+": this.getMinutes(), //分 
        "s+": this.getSeconds(), //秒 
        "q+": Math.floor((this.getMonth() + 3) / 3), //季度 
        "S": this.getMilliseconds() //毫秒 
    };
    if (/(y+)/.test(fmt)) fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));
    for (var k in o)
    if (new RegExp("(" + k + ")").test(fmt)) fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));
    return fmt;
}

获取前一天 后一天的例子

//调用 getDay(-1,'day','2014-10-12') 前一天; getDay(+1,'day','2014-10-12') 后一天;

// 计算时间
function getDay(n, flag, str) {

	var day = strToDate(str);
	var curentMonth = day.getMonth() + 1;
	var strYear = day.getFullYear();
	// 今天几号
	var strDate = '';
	var strMonth = '';
	// 返回结果时间
	var strday = '';
	if (flag == 'day') {
		strDate = day.getDate() + n;
		// 跳到下个月
		if (strDate > 31) {
			strDate = 1;
			strMonth = curentMonth + 1;
		} // 跳到上个月
		else if (strDate < 1) {
			strMonth = curentMonth - 1;
			if (strMonth == 4 || strMonth == 6 || strMonth == 9
					|| strMonth == 11) {
				strDate = 30;
			} else if (strMonth == 2) {
				if ((strYear % 4 == 0 && strYear % 100 != 0)
						|| (strYear % 100 == 0 && strYear % 400 == 0)) {
					strDate = 29;
				} else {
					strDate = 28;
				}
			} else {
				strDate = 31;
			}
		} else {
			strMonth = curentMonth;
		}
		// 跳到下一年
		if (strMonth == 13) {
			strYear += 1;
			strMonth = 1;
		}
		// 跳到上一年
		if (strMonth == 0) {
			strYear -= 1;
			strMonth = 12;
			strDate = 31;
		}
		// 处理类型2012-01-01格式
		strMonth = strMonth < 10 ? "0" + strMonth : strMonth;
		strDate = strDate < 10 ? "0" + strDate : strDate;
		// 拼接日期字符串
		strday = strYear + "-" + strMonth + "-" + strDate;
	}
	// 计算下个月上个月
	if (flag == 'month') {
		strMonth = curentMonth + n;
		// 处理类型2012-01-01格式
		strMonth = strMonth < 10 ? "0" + strMonth : strMonth;
		strday = strYear + "-" + strMonth;
	}
	return strday;
}
// 日期字符串转date
function strToDate(str) {
	var regEx = new RegExp("\\-", "gi");
	// dependedVal必须是 2014/12/12的格式
	dependedVal = str.replace(regEx, "/");
	var milliseconds = Date.parse(dependedVal);
	var dependedDate = new Date();
	dependedDate.setTime(milliseconds);
	return dependedDate;
}

获取上一周 下一周的方法

//获取日期差
	function getDate(date, dayspan)
    {
        var time = date.valueOf();
        time += (dayspan * 24 * 60 * 60 * 1000);
        return new Date(time);
    }
	// w为0为当前周,1为下周，-1为上周
	function getWeek(w) {
		var date = new Date();
		var x = date.getDay();
		var msg = "";
		var weekFirst = getDate(date, w * 7 - x+1);
		var weekLast = getDate(date, 6 - x + w * 7+1);
		var firstMonth = eval(weekFirst.getMonth() + 1)>=10?eval(weekFirst.getMonth() + 1):"0"+eval(weekFirst.getMonth() + 1);
		var lastMonth = eval(weekLast.getMonth() + 1)>=10?eval(weekLast.getMonth() + 1):"0"+eval(weekLast.getMonth() + 1);
		//一周的开始时间
		msg = weekFirst.getFullYear() + "-" + firstMonth
				+ "-" + (weekFirst.getDate()>=10?weekFirst.getDate():"0"+weekFirst.getDate());
		//一周的结束时间
		msg += "=" + weekLast.getFullYear() + "-"
				+ lastMonth + "-" + (weekLast.getDate()>=10?weekLast.getDate():"0"+weekLast.getDate());

		return msg;
	}

获得某年的某月总共有多少天

function getLastDay(year, month) {
	var new_year = year;
	var new_month = parseInt(month, 10);
	var new_date = new Date(new_year, new_month, 1);
	return (new Date(new_date.getTime() - 1000 * 60 * 60 * 24)).getDate();
}