Zone method from time package doesn't return updated timezone if timezone is changed during process execution

I have written below a simple Go code to get the system timezone. It works fine and returns the system's current timezone. The issue is if I change the timezone in-between process execution then it doesn't return the updated timezone. It returns only the old timezone.

package main

import (
	"fmt"
	"time"
)

func main() {
    
    for i := 0; i < 10; i++ {
		t := time.Now()
        zone, offset := t.Zone()
        fmt.Println(zone, offset)
        z, _ := t.Zone()
        fmt.Println("timezone", z)
	}
}

if you have a look at the source code of the time package, you can find that the local Location is set once at the start of the application, by a sync.Once (or more precisely: when the tz information is obtained by a call to .get() for the first time):

// localLoc is separate so that initLocal can initialize
// it even if a client has changed Local.
var localLoc Location
var localOnce sync.Once

func (l *Location) get() *Location {
	if l == nil {
		return &utcLoc
	}
	if l == &localLoc {
		localOnce.Do(initLocal)
	}
	return l
}

Now, initLocal is platform-dependent since different platforms handle time zones differently; for example for Windows you have:

func initLocal() {
	var i syscall.Timezoneinformation
	if _, err := syscall.GetTimeZoneInformation(&i); err != nil {
		localLoc.name = "UTC"
		return
	}
	initLocalFromTZI(&i)
}

From here on, you could work your way through the source code to get an idea how you can implement this for your application. For example on Windows, you could get the UTC offset in minutes by calling the Bias and DaylightBias fields of the syscall.Timezoneinformation struct.

Thanks, @MrFuppes

The issue got resolved by calling Win32 API from Golang. Below is the code snippet.

package main
import (
"fmt"
"time"
"syscall"
"strconv"
"unicode/utf16"
)
func main() {
for index := 0; index < 10; index++ {
now := time.Now()
timeZone, _ := now.Zone()
fmt.Println("timezone", timeZone)
var itz syscall.Timezoneinformation
if _, err := syscall.GetTimeZoneInformation(&itz); err != nil {
fmt.Println("GetTimeZoneInformation failed")
}
fmt.Println(strconv.Itoa(int(itz.Bias)))
var newBytes []uint16
const intBits = 4 + 4*(^uint(0)>>63)
if intBits == 4 {
//For 32 bit
bytes := itz.StandardName
for i := 0; i < len(bytes); i++ {
c := bytes[i]
if c == 0 {
break
}
newBytes = append(newBytes, c)
}
} else if intBits == 8 {
//For 64 bit
bytes := itz.StandardName
for i := 0; ; i++ {
c := bytes[i]
if c == 0 || i == 2048 {
break
}
newBytes = append(newBytes, c)
}
}
tzName := string(utf16.Decode(newBytes))
fmt.Println("Timezone StandardName: ", tzName)
}
}