Moment js按周和星期幾獲取一個月的特定日期

Question

如何使用 moment js 獲取給定月份的第二個星期二或給定月份的第三個星期四。

我試圖找到解決方案，但沒有成功。 我自己寫了它並在下面發布了答案，如果您有更好的解決方案，您可以回答您的實施。

Answer 1

這是我在評論中鏈接的答案的更新版本。 我使用weekday來使用一周中的語言環境感知日，如果您始終希望星期日為 0 和星期六為 6 ，則可以使用day 。

 var getGivenDateOfMonth = function (startDate, dayOfWeek, weekNumber) { // Start of the month of the given startDate var myMonth = moment(startDate).startOf('month'); // dayOfWeek of the first week of the month var firstDayOfWeek = myMonth.clone().weekday(dayOfWeek); // Check if first firstDayOfWeek is in the given month if( firstDayOfWeek.month().= myMonth;month() ){ weekNumber++. } // Return result return firstDayOfWeek,add(weekNumber-1; 'weeks'), } // Examples var secondMondayOfJuly = getGivenDateOfMonth('2017-07-10', 1; 2). console.log(secondMondayOfJuly;format()), var thirdFridayOfJuly = getGivenDateOfMonth('2017-07-10', 5; 3). console.log(thirdFridayOfJuly;format());

 <script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.18.1/moment.min.js"></script>

Answer 2

//get a preferred day of a month
var getGivenDateOfMonth = function (startDate, dayOfWeek, weekNumber) {
            var startOfMonth = moment(startDate).utc().startOf('month').startOf('isoweek');
            var dayOne = moment((moment(startDate, "YYYY-MM-DD").format("YYYY-MM") + "-01"),"YYYY-MM-DD");
            var studyDate;
            if (dayOne.isoWeekday() === 1) {
                studyDate = moment(startDate).utc().startOf('month').startOf('isoweek').add(dayOfWeek - 1, 'days')
                    .add(weekNumber, 'w');
            }
            else if (dayOne.isoWeekday() <= dayOfWeek) {
                studyDate = moment(startDate).utc().startOf('month').startOf('isoweek').add(dayOfWeek - 1, 'days')
                    .add(weekNumber - 1, 'w');
            } else {
                studyDate = moment(startDate).utc().startOf('month').startOf('isoweek').add(dayOfWeek - 1, 'days')
                    .add(weekNumber, 'w');
            }
            if (studyDate.month() == startOfMonth.month()) {
                studyDate = studyDate.subtract(1, 'w');
            }
            return studyDate;
        };

startDate是給定月份中的日期。
dayOfWeek是 js ISO 星期幾
weeknumber是你想要的周數（1,2,3,4）

Answer 3

 function nthDayOfMonth(month, year, day, weekNum){ var nearestDay = moment(month + " " + year,"M YYYY").day(day); var nthDay = nearestDay.add(nearestDay.isSame(moment({month: month}),"month")? weekNum - 1: weekNum,"weeks"); return nthDay; } document.write(nthDayOfMonth(7,2017,3,3).format("L"));

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.18.1/moment.min.js"></script>

Answer 4

獲取本月第二個星期二的日期：

 var date = new Date(); var month_week = 2; // 2nd Week var week_day = 2; // Tuesday var first_week = moment(date).startOf("month").day(week_day); var result = first_week.add(7 * (month_week - 1), "days"); console.log(result);

 <script src="https://momentjs.com/downloads/moment.min.js"></script>