js 获取某一年的所有自然周
2018-08-15 本文已影响137人
爱吃荔枝的张长弓
<html>
<head>
<title></title>
<meta charset="UTF-8" />
</head>
<body>
<script>
'use strict';
function formatDig(num){
return num>9?''+num:'0'+num;
}
function formatDate(mill){
var y=new Date(mill);
let raws= [
y.getFullYear(),
formatDig(y.getMonth()+1),
formatDig(y.getDate()),
y.getDay()||7
];
let format=['年','月','日 星期'];
return String.raw({raw:raws},...format);
}
function* createWeeks(year){
const ONE_DAY=24*3600*1000;
let start=new Date(year,0,1),
end=new Date(year,11,31);
let firstDay=start.getDay()|| 7,
lastDay=end.getDay()||7;
let startTime=+start,
endTime=startTime+(7-firstDay)*ONE_DAY,
_endTime=end-(7-lastDay)*ONE_DAY;
yield [startTime,endTime];
startTime=endTime+ONE_DAY;
endTime=endTime+7*ONE_DAY;
while(endTime<_endTime){
yield [startTime,endTime];
startTime=endTime+ONE_DAY;
endTime=endTime+7*ONE_DAY;
}
yield [startTime,+end];
}
let index=1;
for(let i of createWeeks(2016)){
let start=i[0],
end=i[1];
console.log(`第${formatDig(index++)}周 ${formatDate(start)}-${formatDate(end)}`);
}
</script>
</body>
</html>
