code: func builtinUTCDate(args []types.Datum, _ context.Context) (d types.Datum, err error) {
  	year, month, day := time.Now().UTC().Date()
  	t := types.Time{
  		Time: types.FromGoTime(time.Date(year, month, day, 0, 0, 0, 0, time.UTC)),
  		Type: mysql.TypeDate, Fsp: types.UnspecifiedFsp}
  	d.SetMysqlTime(t)
  	return d, nil
  }
docs: // See https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_utc-date