time: tzinfo for Thailand not present

[zhexuany]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version go1.10.3 darwin/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/zhexuany/Library/Caches/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/zhexuany/repo/go"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.10.3/libexec"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.10.3/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/t9/s5qvdzpx3h5g58xzpm5gn8l00000gn/T/go-build676470505=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

In Thailand, I ran the following code:

package main

import (
        "fmt"
	"time"
	)

func main() {
	t := time.Now()
	fmt.Println(t.String())
}

If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best.

What did you expect to see?

2018-06-24 12:17:01.930111356 +0700 ICT m=+0.000337067

What did you see instead?

2018-06-24 12:17:01.930111356 +0700 +07 m=+0.000337067

[zhexuany]

Thailand is currently using timezone called ICT. I, personally, feel like it is better to return time(in string, of course) with a timezone name ICT rather than +07.

[agnivade]

We just updated the vendored tzdata a couple of days ago. Is it possible for you to try with the master branch ?

[agnivade]

NVM, just checked src/time/zoneinfo_abbrs_windows.go. It's not there.

@bradfitz - Should we update that file after bb222cd ?

[ALTree]

This is working as intended.

The name of the timezone is UTC+07:00. The invented three-letter abbreviations are being removed from the tzdata database in favour of the offset names (+07, in this case). We didn't decide this, it's the policy that has been adopted upstream. It started in the 2017a release.

Additionally, as of tzdata-2017a there has been a policy of removal of zone abbreviations where these abbreviations have no official standing and were invented for convenience.

The tzdata 2017a changelog says:

Switch to numeric time zone abbreviations for South America, as
part of the ongoing project of removing invented abbreviations.
[...] Similarly, switch from invented to numeric time zone
abbreviations for [...] Indochina [...]

http://mm.icann.org/pipermail/tz-announce/2017-February/000045.html

[zhexuany]

Ah, I did not notice this change.

Under this case, maybe we may need change the behavior time.Parse("20060102-15:04:05 -0700 MST", "20180624 12:17:01 +0700 +07")?

Below is a snippet to reproduce

package main

import (
        "fmt"
	"time"
	)

func main() {
	if _, err := time.Parse("20060102-15:04:05 -0700 MST", "20180624-12:17:01 +0700 +07"); err != nil {
		fmt.Println(err)
	}
}

It returns a error complaining parsing time "20180624-12:17:01 +0700 +07" as "20060102-15:04:05 -0700 MST": cannot parse "+07" as "MST"

[agnivade]

Ah thanks for the clarification @ALTree.

Also, please correct me if I am wrong - don't we need to re-run genzabbrs.go after updating the zoneinfo.zip file ?

[ALTree]

@zhexuany This is #24071 and it's already fixed on tip (see CL 98157). The code above doesn't print an error in go1.11 (to be released soon).

[ALTree]

@agnivade Possibly? It looks like it's only needed for windows and I don't use it so I'm not sure... @alexbrainman committed all that contraption. Alex, can you help us? When should genzabbrs.go be run?

I just tried it and git diff shows several changes, so it appears that the zoneinfo_abbrs_windows.go may indeed be outdated.

[zhexuany]

gotcha. Closing this issue since such bug was already fixed. A lot thanks to @ALTree

[alexbrainman]

@alexbrainman committed all that contraption

Guilty as charged.

When should genzabbrs.go be run?

You can run it any time. It uses current version of http://unicode.org/cldr/data/common/supplemental/windowsZones.xml and your $GOROOT/lib/time/zoneinfo.zip file.

Alex

[ALTree]

@alexbrainman thanks! I sent a change: https://go-review.googlesource.com/c/go/+/120559