Get a time zone offset from a time zone name

tz_testing.go

// +build testing

package main
import "C"
import "time"

//export time_zone_offset_seconds
func time_zone_offset_seconds(tzName *C.char) C.int {
	location, err := time.LoadLocation(C.GoString(tzName))
	if err != nil {
		panic(err)
	}
	_, offset := time.Now().In(location).Zone()
	return C.int(offset)
}