const (
 ANSIC    = "Mon Jan _2 15:04:05 2006"
 UnixDate  = "Mon Jan _2 15:04:05 MST 2006"
 RubyDate  = "Mon Jan 02 15:04:05 -0700 2006"
 RFC822   = "02 Jan 06 15:04 MST"
 RFC822Z   = "02 Jan 06 15:04 -0700" // RFC822 with numeric zone
 RFC850   = "Monday, 02-Jan-06 15:04:05 MST"
 RFC1123   = "Mon, 02 Jan 2006 15:04:05 MST"
 RFC1123Z  = "Mon, 02 Jan 2006 15:04:05 -0700" // RFC1123 with numeric zone
 RFC3339   = "2006-01-02T15:04:05Z07:00"
 RFC3339Nano = "2006-01-02T15:04:05.999999999Z07:00"
 Kitchen   = "3:04PM"
 // Handy time stamps.
 Stamp   = "Jan _2 15:04:05"
 StampMilli = "Jan _2 15:04:05.000"
 StampMicro = "Jan _2 15:04:05.000000"
 StampNano = "Jan _2 15:04:05.000000000"
)

package timeutil

import "time"

var (
 cst *time.Location
)

// CSTLayout China Standard Time Layout
const CSTLayout = "2006-01-02 15:04:05"

func init() {
 var err error
 if cst, err = time.LoadLocation("Asia/Shanghai"); err != nil {
 panic(err)
 }
}

// RFC3339ToCSTLayout convert rfc3339 value to china standard time layout
func RFC3339ToCSTLayout(value string) (string, error) {
 ts, err := time.Parse(time.RFC3339, value)
 if err != nil {
 return "", err
 }

 return ts.In(cst).Format(CSTLayout), nil
}

RFC3339Str := "2020-11-08T08:18:46+08:00"
cst, err := timeutil.RFC3339ToCSTLayout(RFC3339Str)
if err != nil {
 fmt.Println(err)
}
fmt.Println(cst)