JavaScript的dateDate是1，时区偏移的问题？

Question

I have the following code:

let date = new Date(event.eventDate); //2018-02-12T00:00:00.000Z
date = date.toISOString(); //try random thing here, but not helpful
date = new Date(date.split('T')[0]);
console.log(date, date.getDate()); //output is 11 on my local computer

so 2018-02-12 , getDate should be 12, but somehow on my local computer it returns 11.

However, when i run the same code on remote server, it outputs getDate() correctly, which is "12".

how do i make sure the out put is always "12" no matter where i run the code?

Thanks!

Answer 1

getDate is interpretting the date in your local timezone, which is a few hours behind the UTC version of the date, which your server is using. Since the time of the date is midnight, the offset of your local timezone sets it to the prior day. You can replace getDate with getUTCDate to use the UTC value

let date = new Date(event.eventDate); //2018-02-12T00:00:00.000Z
console.log(date.getUTCDate()) // 12

Answer 2

According to MDN:

The getDate() method returns the day of the month for the specified date according to local time.

If you're looking for a fixed (UTC) date that will be the same for each person, you can use getUTCDate() :

 let date = new Date('2018-02-12T00:00:00.000Z'); date = date.toISOString(); date = new Date(date.split('T')[0]); console.log(date, date.getDate()); console.log(date, date.getUTCDate()); 

Hope this helps!