Javascript如何在使用时区时通过getDay验证日期

Question

我试图验证一周中的某一天是否等于星期三 (3)，如果我按以下方式操作，这很有效。var today = new Date();if (today.getDay() == 3) {  alert('Today is Wednesday');} else {    alert('Today is not Wednesday');}但我无法对时区做同样的事情。var todayNY = new Date().toLocaleString("en-US", {timeZone: "America/New_York"});if (todayNY.getDay() == 3) {  alert('Today is Wednesday in New York');} else {    alert('Today is not Wednesday in New York');}

Answer 1

new Date().toLocaleString()根据特定于语言的约定返回表示给定日期的字符串。所以可以这样做

var todayNY = new Date();

var dayName = todayNY.toLocaleString("en-US", {

    timeZone: "America/New_York",

    weekday: 'long'

})

if (dayName == 'Wednesday') { // or some other day

    alert('Today is Wednesday in New York');

} else {

    alert('Today is not Wednesday in New York');

}

Answer 2

正如函数“toLocaleString”所暗示的那样，它返回一个字符串。'getDay' 存在于 Date 类型。

因此，要使用“getDay”，您需要将字符串转换回日期。

尝试：

var todayNY = new Date().toLocaleString("en-US", {

  timeZone: "America/New_York"

});

todayNY = new Date(todayNY);

if (todayNY.getDay() == 3) {

  alert('Today is Wednesday in New York');

} else {

  alert('Today is not Wednesday in New York');

}