Why is new Date() returning the wrong timezone in Chrome? [duplicate]

Question

userAgent：`Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.7 Safari/537.36`

In Chrome Devtools, running new Date(1899, 1, 10) will yield the string:

Fri Feb 10 1899 00:00:00 GMT+0805 (中国标准时间)

But in other browsers it returns:

Fri Feb 10 1899 00:00:00 GMT+0800 (中国标准时间)

0800 is correct. Why does 0805 appear?

Answer 1

Looking at this website, for Shanghai, they had a GMT+0805 from < 1800 up to 1900.

This changed in 1901 when they removed the extra 5 minutes, becoming GMT+0800.

Same reason why user Thum Choon Tat gets GMT+0646. in the comments.

This said, it looks like Chrome goes a little further than other browsers in determining the timezone.