C# js获取当前日期为当前月/年/季度的第几周（自然周）

<script type="text/javascript">

var today = new Date();//获取当前时间
var y = today.getFullYear();
var m = today.getMonth()+1;
var d = today.getDate();
document.write("今天是：",y,"-", m, "-", d, "<br/>");
document.write( "今天是",y,"年的第 ", getYearWeek(y, m, d), " 周<br/>" );
document.write( "今天是",m,"月的第 ", getMonthWeek(y, m, d), " 周<br/>" );
var quarter = "";
var result = getYearWeek(y, m, d);
if (m <4) {
    quarter = 1;
    week = result;
}

else if (m < 7) {

   quarter = 2;
   week = result - getYearWeek(y, 4, 1);
    var day = new Date(y, 4, 1);
if (day.getDay() > 1) {
    week += 1;
}
} else if (m < 10) {
   quarter = 3;
   week = result - getYearWeek(y, 7, 1);
   var day = new Date(y, 7, 1);
if (day.getDay() > 1) {
  week += 1;
}
} else {
   quarter = 4;
   week = result - getYearWeek(y, 10, 1);
   var day = new Date(y, 10, 1);
if (day.getDay() > 1) {
   week += 1;
}
}
document.write( "今天是第",quarter,"季度的第 ", week, " 周" );

//今天是当前月的第几周
var getMonthWeek = function (a, b, c) {
   var date = new Date(a, parseInt(b) - 1, c), w = date.getDay(), d = date.getDate();
   return Math.ceil( (d + 6 - w) / 7 );
};
//今天是当前年份的第几周（自然周）
var getYearWeek = function (a, b, c) {
   var date1 = new Date(a, parseInt(b) - 1, c), date2 = new Date(a, 0, 1),
   d = Math.round((date1.valueOf() - date2.valueOf()) / 86400000);
   return Math.ceil( (d + ((date2.getDay() + 1) - 1)) / 7 );
};

</script>