Question

我想在javascript中获取两个日期之间的日历周差异。

示例：

a='09-May-2018'
b='14-May-2018'

这两个日历周的差异是2。

我开始将日期转换为瞬间，并通过Moment.js diff方法获得周数差异。但这是考虑7天为一周，并给我一个以上的例子。

我想到得到一周的时刻然后减去它。但在那，如果日期是两个不同的年份。我会得到错误的结果。与'01-Jan-2017'和'01-Jan-2018'一样，周数为1。

有没有更好的方法有效地做到这一点？

Answer 1

获取一周的开始日期，并使用b1.diff(a1,'week');

查找周差异

function getWeekDiff(day1,day2){
 var a1 = moment(day1, "DD-MMM-YYYY").startOf('week');
 var b1 = moment(day2, "DD-MMM-YYYY").startOf('week');
 var weekDiff = b1.diff(a1,'week');
 console.log(weekDiff);
 return weekDiff;
}

getWeekDiff("09-May-2018", "14-May-2018");
getWeekDiff("01-Jan-2017", "01-Jan-2018");
getWeekDiff("08-May-2018", "08-May-2018");

<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.20.1/moment.js"></script>

Answer 2

您还可以在普通javascript中计算周差异。由于你还没有完全解释如何确定我做出一些猜测的周数的规则。以下内容：

将星期的第一天默认为星期一
复制日期并将其移至星期一开始
确定d0在d1之前
将周数计算为1 + (endDate - startDate) / 7
可以使用可选的第3个参数设置星期开始的日期：0 =星期日，1 =星期一等。
结果总是积极的。如果日期在同一周，则差异为1.

仅当结束日期在开始日期之后才能正常工作。

/* Calculate weeks between dates
** Difference is calculated by getting date for start of week,
** getting difference, dividing and rounding, then adding 1.
** @param {Date} d0 - date for start
** @param {Date} d1 - date for end
** @param {number} [startDay] - default is 1 (Monday)
** @returns {number} weeks between dates, always positive
*/
function weeksBetweenDates(d0, d1, startDay) {

  // Default start day to 1 (Monday)
  if (typeof startDay != 'number') startDay = 1;

  // Copy dates so don't affect originals
  d0 = new Date(d0);
  d1 = new Date(d1);

  // Set dates to the start of the week based on startDay
  [d0, d1].forEach(d => d.setDate(d.getDate() + ((startDay - d.getDay() - 7) % 7)));

  // If d1 is before d0, swap them
  if (d1 < d0) {
    var t = d1;
    d1 = d0;
    d0 = t;
  }

  return Math.round((d1 - d0)/6.048e8) + 1;
}

console.log(weeksBetweenDates(new Date(2018, 4, 9), new Date(2018, 4, 14)));

Answer 3

我有一个要求，如果差异大于12周，我必须采取一些行动。所以我通过逐周（）方法得到它。像这样：

Math.abs(endDate.diff(startDate, 'days'))<91 &&
  Math.abs(startDate.week() - endDate.week()) < 12)

Answer 4

使用moment.js，根据https://momentjs.com/docs/#/durations/diffing/

/**
* @param fromDate - moment date
* @param toDate - moment date
* @return {int} diffInWeeks Diff between dates with weeks as unit
**/
const getDiffInWeeks = (fromDate, toDate) => {
    const requestedOffset = 1
    const diff = toDate.diff(fromDate);
    const diffInWeeks = moment.duration(diff).as('weeks')
    return Math.ceil(diffInWeeks) + requestedOffset
}

如何获得两个时刻之间的日历周差异？

4 个答案: