new Date().getTimezoneOffset() 返回错误的时区

Question

I am in Israel, so my offset right now should be 120 . Yet, when I use new Date().getTimezoneOffset() , I get back -120 , so not just a daylight savings issue. Should I simply change every minus to plus and vice versa? I don't know what might be the case for users in other timezones.

That's my function:

  firebase
    .database()
    .ref("words/" + newPostKey)
    .set({
      word,
      length: word.length,
      time_to_action: timeToAction,
      output: output,
      lang: project.lang,
      country: project.country,
      user: userUID,
      timestamp : Date.now(),
      timezone_offset : new Date().getTimezoneOffset()
    });

and timezone_offset is what gets saved as -120 . I am in Tel Aviv.

Answer 1

Well, I live in Ukraine and even if we have (UTC + 02: 00) now we are ahead of UTC by 3 hours cause we have 'winter time', when clocks are set back by one hour. So new Date().GetTimezoneOffset() returned '-120' , while new Date(0).getTimezoneOffset() returned '-180' . Maybe that's the case you faced with.

Answer 2

getTimezoneOffset() is working well. This function retuns the number of minutes you have to add to your current time to get the UTC time, so in GMT+X the result is negative.

Answer 3

Yes. You are ahead of GMT by 2 hours therefor to get back to GMT you have to subtract 120 minutes. Your offset is -120.