js中date日期的使用总结

赋某日期为日期类型	new Date(myYear,myMonth,myDate);//当myDate为0时，返回当前月份的上月末日期
当前日期 now	new Date()
当前日期为本周的第几天,星期三返回3 nowDayOfWeek	now.getDay()
当前日 nowDay	now.getDate()
当前月 nowMonth	now.getMonth();//0为一月，1为2月，...
当前年 nowYear	nowYear = now.getYear(); nowYear += nowYear<2000?1900:0;
格式化日期：yyyy-MM-dd	function formatDate(date,fmt) {  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);  }
格式化日期：任意格式	function dateFtt(fmt,date) {   var o = {     "M+" : date.getMonth()+1, //月份     "d+" : date.getDate(), //日     "h+" : date.getHours(), //小时     "m+" : date.getMinutes(), //分     "s+" : date.getSeconds(), //秒     "q+" : Math.floor((date.getMonth()+3)/3), //季度     "S" : date.getMilliseconds() //毫秒   };   if(/(y+)/.test(fmt))     fmt=fmt.replace(RegExp.$1, (date.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; }
两个日期间的间隔天数	function getMonthDays(myMonth){ //此处计算的是一个月的天数 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;  }
本周的开始日期  weekStartDate	new Date(nowYear, nowMonth, nowDay - nowDayOfWeek);
本周的结束日期  weekEndDate	new Date(nowYear, nowMonth, nowDay + (6 - nowDayOfWeek));
本月初 monthStartDate	new Date(nowYear, nowMonth, 1);
	now.setDate(1);
本月末 monthEndDate	var = new Date(nowYear, nowMonth, getMonthDays(nowMonth));
本月所属季度 nowQuarter	nowMonth ++; parseInt(nowMonth/3+(nowMonth%3==0?0:1))
	nowMonth ++; Math.ceil(nowMonth/3)
上月初 lastMonthStart	new Date(nowYear, lastMonth, 1);
	lastMonthDate = new Date(); lastMonthDate.setDate(1); lastMonthDate.setMonth(lastMonthDate.getMonth()-1)
	new Date(myYear,myMonth-1,1)
上月末 lastMonthEnd	new Date(nowYear, lastMonth, getMonthDays(lastMonth));
	new Date(myYear,myMonth,0);
本季度开始月份 quarterStartMonth	if(nowMonth<3){  return 0;  }else if(2<nowMonth && nowMonth<6){  return 3;  }else if(5<nowMonth && nowMonth<9){  return 6;  }else{ //if(nowMonth>8){  return 9;  }
本季度的开始日期 quarterStartDate	new Date(nowYear, quarterStartMonth, 1);
本季度的结束日期 quarterEndDate	var quarterEndMonth = quarterStartMonth + 2;  var quarterStartDate = new Date(nowYear, quarterEndMonth, getMonthDays(quarterEndMonth));
	var quarterEndMonth = quarterStartMonth + 2;  var quarterStartDate = new Date(nowYear, quarterEndMonth+1, 0);
取与今天偏差为o天的日期	new Date(now.getTime()+o*24*60*60*1000)