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');}