获取dd.mm.yyyy格式的母亲节日期

Question

我试着用Javascript获取母亲节的日期(五月的第一个星期天)。但是我的代码的结果是0.4.2021。错误在哪里，或者有一种更简单的方法来获取母亲节日期(dd.mm.yyyy) (德国时区)。

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var currentYear = new Date().getFullYear()
var mayFirst = new Date(currentYear + '-05-01');
var dayOfWeek = mayFirst.getUTCDay();
var firstSunday;
if (dayOfWeek === 0) {
    firstSunday = mayFirst;
} else {
    firstSunday = new Date();
    firstSunday.setDate(1 + (7 - dayOfWeek));
}
var mothersDay = new Date(firstSunday);
mothersDay.setDate(firstSunday.getUTCDate() + 7);
mothersDay = new Date(mothersDay);

console.log(mothersDay.getDay() + "." + mothersDay.getMonth() + "." + mothersDay.getFullYear());

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Answer 1

下面是执行此操作的正确方法，无需进行容易出错的计算或字符串连接，包括将其格式化为DD.MM.YYYY：

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// Mother's Day is the second sunday in May
const d = new Date();
d.setMonth(4); // May
d.setDate(8); // May 8 is the earliest possible date
// while not a sunday, move to next day 
while (d.getUTCDay()) d.setDate(d.getDate() + 1);

const result = new Intl.DateTimeFormat('de-DE', { day: "2-digit", month: "2-digit", year: "numeric"}).format(d);

document.body.innerHTML += result;

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Answer 2

getMonth()是基于0的，所以你需要加1。此外，您还希望使用getDate()而不是getDay()来获取日期的日期值。

我假设你想得到5月的第二个星期天，因为你的代码中的下面这行代码加上了7天。如果你想要第一个星期天，你也应该删除这一行。

mothersDay.setDate(firstSunday.getUTCDate() + 7);

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var currentYear = new Date().getFullYear()
var mayFirst = new Date(currentYear + '-05-01');
var dayOfWeek = mayFirst.getUTCDay();
var firstSunday;
if (dayOfWeek === 0) {
    firstSunday = mayFirst;
} else {
    firstSunday = new Date();
    firstSunday.setDate(1 + (7 - dayOfWeek));
}
var mothersDay = new Date(firstSunday);
mothersDay.setDate(firstSunday.getUTCDate() + 7);

mothersDay = new Date(mothersDay);

console.log(mothersDay.getDate() + "." + (mothersDay.getMonth() + 1) + "." + mothersDay.getFullYear());

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