使用操作（add / sub）的Moment.js返回错误的TZ

Question

My issue was very similar to this thread: Moment.js diff between UTC dates and I see the bug was fixed ( 2 years ago ha https://github.com/moment/moment/issues/261 )

I experience a strange & similar issue when using version 2.5.1 of "moment.js" & version 0.0.2 of "moment-timezones.js"

var now  = moment.tz("2014-03-20 12:00", "EST5EDT"); // date & a pre-defined TZ
console.log(now.format());  // 2014-03-20T12:00:00-04:00

Issue was found when using this order:

now.utc()                   // Converting to UTC
console.log(now.format());  // 2014-03-20T16:00:00+00:00

now.subtract('days', 3);    // Subtract
console.log(now.format());  // 2014-03-17T16:00:00-04:00

Problem: original TZ (-04:00) was suddenly assigned after "subtract"

Bypassed the issue by first "subtract"ing "now" and then converting to UTC

console.log(now.format());  // 2014-03-20T12:00:00-04:00
now.subtract('days', 3);    // Subtract
console.log(now.format());  // 2014-03-17T12:00:00-04:00

now.utc()                   // Converting to UTC
console.log(now.format());  // 2014-03-17T16:00:00+00:00

Is this a bug or I'm using moment() in the wrong way ?

Answer 1

这可能有效！

moment("2014-03-20 12:00").subtract('days', 3).tz("EST5EDT").format()