time.go
func (t Time) Value() (driver.Value, error) {
	if !t.Valid {
		return nil, nil
	}
	return t.Time, nil
}
func (t Time) Value() (driver.Value, error) {
	if !t.Valid {
		return nil, nil
	}
	return t.Time, nil
}
// Value implements the driver Valuer interface.