time: uninitialized time object produce unexpected conversion for trying to convert timezone with "func (t Time) In(loc *Location) Time"

[gopherbot]

by nash.tsai:

What does 'go version' print?
go version go1.3.1 darwin/amd64

What happened?

package main

import (
    "time"
)

func main() {
    var t time.Time
    println ("t:", t.String(), "t in Local:", t.In(time.Local).String())
}

output:
t: 0001-01-01 00:00:00 +0000 UTC t in Local: 0001-01-01 08:26:44 +0826 LMT

What should have happened instead?

My timezone is +8 so I would expect:  "0001-01-01 08:00:00 +0800"

[robpike]

Comment 1:

Something is funny in your example: it's using local mean time, not a proper time zone.
I tried this in California and got
    t: 0001-01-01 00:00:00 +0000 UTC t in Local: 0000-12-31 16:00:00 -0800 PST
which is what I would expect.
Your result makes sense if you have no time zone data beyond LMT and you are in the
middle of a time zone, as LMT is local mean time. I suspect the time zone data on the
machine isn't right.

[gopherbot]

Comment 2 by nash.tsai:

The OS is OS X 10.9.4, and the timezone settings it set to auto timezone as per
screenshot attachment.

Attachments:

1. Screen Shot 2014-08-26 at 4.01.47 PM.png (102184 bytes)

[gopherbot]

Comment 3 by nash.tsai:

I've tried to my timezone to Taipei, and it worked as expected:
t: 0001-01-01 00:00:00 +0000 UTC t in Local: 0001-01-01 08:00:00 +0800 CST
And anywhere in China will cause this problem.

[gopherbot]

Comment 4 by nash.tsai:

I've tried to set my timezone to Taipei, and it worked as expected:
t: 0001-01-01 00:00:00 +0000 UTC t in Local: 0001-01-01 08:00:00 +0800 CST
And anywhere in China will cause this problem.

[griesemer]

Comment 5:

Labels changed: added repo-main.

[donlzx]

Doesn't matter if the time is initialized or not.

What does 'go version' print?

go version go1.4.1 linux/amd64

What happened?

package main

import (
    "fmt"
    "time"
)

func main() {
    t, _ := time.Parse("20060102", "19000101")
    fmt.Println("t:", t.String(), "t in Local:", t.In(time.Local).String())
}

t: 1900-01-01 00:00:00 +0000 UTC t in Local: 1900-01-01 07:36:42 +0736 LMT

On Linux Mint 17 Qiana, local time zone is Hong Kong (HKT)

[minux]

Note the reference time in time.Parse is wrong (should be "20060102"),
although it doesn't matter for this example.

@donlzx, your example is working as intended. It's because Hong Kong
was indeed using LMT with GMT offset of 7:36:42 until 1904 Oct 30, at
least according to the latest tzdata for Asia/Hong_Kong.

I think this issue is mostly due to the fact that some people are not aware
that the correct time zone actually depends on the date and it's not
necessarily the same as the current timezone in use.

I'm going to close this issue as working as intended.