di-shan-utils
Version:
JavaScript 函数库、工具类
25 lines (20 loc) • 636 B
JavaScript
var staticDayTime = require('./staticDayTime')
var toStringDate = require('./toStringDate')
var isValidDate = require('./isValidDate')
/**
* 返回某个年份的第几周
*
* @param {Date} date 日期或数字
* @return {Number}
*/
function getYearWeek (date) {
date = toStringDate(date)
if (isValidDate(date)) {
date.setHours(0, 0, 0, 0)
date.setDate(date.getDate() + 3 - (date.getDay() + 6) % 7)
var week = new Date(date.getFullYear(), 0, 4)
return Math.round(((date.getTime() - week.getTime()) / staticDayTime + (week.getDay() + 6) % 7 - 3) / 7) + 1
}
return NaN
}
module.exports = getYearWeek