code: func (d *Date) UnmarshalText(text []byte) error {
  	if len(text) == 0 {
  		return nil
  	}
  	dd, err := time.Parse(RFC3339FullDate, string(text))
  	if err != nil {
  		return err
  	}
  	*d = Date(dd)
  	return nil
  }
docs: // UnmarshalText parses a text representation into a date type