time: Parse() does not recognize time zone MST

[crufter]

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

Playground one, go version go1.8 darwin/amd64, go version go1.7.3 darwin/amd64, it's all wrong on these.

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

The go env correspoding to the go version go1.7.3 darwin/amd64 version:

GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/crufter/go"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/nm/gx94478n3dq9478jm5ndvpqh0000gn/T/go-build541649718=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"

What did you do?

I put the example code from the time.Parse docs on playground and I see a different output than the output in the doc. https://play.golang.org/p/tuBDbz66I0

What did you expect to see?

2013-02-03 19:54:00 -0800 PST

(Same as in documentation here: https://golang.org/pkg/time/#Parse)

What did you see instead?

2013-02-03 19:54:00 +0000 PST

[ALTree]

The Parse documentation says:

When parsing a time with a zone abbreviation like MST, if the zone abbreviation has a defined offset in the current location, then that offset is used.

and

If the zone abbreviation is unknown, Parse records the time as being in a fabricated location with the given zone abbreviation and a zero offset

and

To avoid such problems, prefer time layouts that use a numeric zone offset, or use ParseInLocation

So you can either use the numeric offset, or call ParseInLocation:

loc, _ := time.LoadLocation("US/Pacific")
const longForm = "Jan 2, 2006 at 15:04 (MST)"
t, _ := time.ParseInLocation(longForm, "Feb 3, 2013 at 19:30 (PST)", loc)
fmt.Println(t)

2013-02-03 19:30:00 -0800 PST

I guess in the documentation it recognizes PST as -08 because it's the godoc tz?

[ianlancetaylor]

Which timezones are recognized depends on the timezone database on your computer.

Timezone names are inherently ambiguous and should be avoided when possible for portability.

Closing because I don't think there is anything to do. Please comment if you disagree.

[crufter]

@ianlancetaylor @ALTree

That explanation makes sense. I did not realise the timezone database is on my computer, hence I found the disparity between my setup and play.golang.org weird.

Thank you