code: func (t *Timedelta) Duration() time.Duration {
  	return t.Days*24*time.Hour +
  		t.Seconds*time.Second +
  		t.Microseconds*time.Microsecond +
  		t.Milliseconds*time.Millisecond +
  		t.Minutes*time.Minute +
  		t.Hours*time.Hour +
  		t.Weeks*7*24*time.Hour
  }
docs: // Duration() returns time.Duration. time.Duration can be added to time.Date.