根据当前指定月份，获取该月份每周的起始日期：
<body>
<input placeholder="请输入" id="time" value="2023-10-01">
<button onclick="computingTime()">计算</button>
<div id="demo"></div>
</body>
<script>
computingTime = () => {
const v = document.getElementById('time').value
let obj = {
1: '一',
2: '二',
3: '三',
4: '四',
5: '五',
6: '六'
}
const time = new Date(v)
const year = time.getFullYear()
const month = time.getMonth() + 1
// 获取当月的第一天
const firstDay = new Date(year, month - 1, 1)
// 获取当月的最后一天
const lastDay = new Date(year, month, 0)
const days = lastDay.getDate() // 多少天
const firstDayOfWeek = firstDay.getDay()
const lastDayWeek = lastDay.getDay()
// 第一天是周日
const weeks = firstDayOfWeek === 0 || lastDayWeek === 1 ? Math.ceil((days) / 7) + 1 : Math.ceil((days + firstDayOfWeek) / 7)
let dates = []
for (let i = 0; i < weeks; i++) {
let start,end
if (firstDayOfWeek === 0) {
start = i === 0 ? (i * 7 + 1) : (i * 7 - 5)
end = Math.min(i === 0 ? start : start + 6, days)
} else {
start = i * 7 - firstDayOfWeek + 2
end = Math.min(start + 6, days)
}
dates.push({
name: '第' + obj[i + 1] + '周',
index: i,
start: start > 0 ? start : 1,
end: end,
time: [start > 0 ? start : 1, end].join('~').replace(/(?=\b\d\b)/g, '0')
})
}
document.getElementById('demo').innerHTML = JSON.stringify(dates)
}
</script>
