time.RFC3339 does not even parse with time.Parse

[wpsmithtwc]

Version: Latest: go version go1.8.3 darwin/amd64
Also reproducible on Go Playground.

What did you do?

https://play.golang.org/p/QvAVXmVMoR

import (
	"fmt"
	"time"
)

func main() {
	if time.RFC3339 == "2006-01-02T15:04:05Z07:00" {
		fmt.Println("These time.RFC3339 == '2006-01-02T15:04:05Z07:00'")
	}
	t, err := time.Parse(time.RFC3339, "2006-01-02T15:04:05Z07:00")
	if err != nil {
		panic(err)
	}
	fmt.Printf("t: %#v\n", t)
}

Result?

The date should parse correctly, but there is an error:

These time.RFC3339 == '2006-01-02T15:04:05Z07:00'
panic: parsing time "2006-01-02T15:04:05Z07:00": extra text: 07:00

goroutine 1 [running]:
main.main()
	/tmp/sandbox164093353/main.go:14 +0x1e0

[ianlancetaylor]

Closing as dup of #9346. Please comment if you disagree.