JavaScript 日期显示错误时区 "GMT+0521 (India Standard Time)"

Question

我有一个简单的问题。

Why JavaScript show's wrong TimeZone if the date is after the year 1906

Please find the below screenshot for the same.

<小时/>

Answer 1

来自维基:https://en.wikipedia.org/wiki/Time_in_India

Though British India did not officially adopt the standard time zones until 1905, when the meridian passing east of Allahabad at 82.5° E longitude was picked as the central meridian for India, corresponding to a single time zone for the country (UTC+5:30). Indian Standard Time came into force on 1 January 1906, and also applied to Sri Lanka (then Ceylon). However, Calcutta time was officially maintained as a separate time zone until 1948 and Bombay time until 1955.[8]

和

Some older time zones were:

Bombay Time (UTC+04:51), Madras Time (UTC+05:21) Calcutta Time (UTC+05:54), Port Blair mean time