code: func (t *Time) FromPackedUint(packed uint64) error {
  	if packed == 0 {
  		t.Time = ZeroTime
  		return nil
  	}
  	ymdhms := packed >> 24
  	ymd := ymdhms >> 17
  	day := int(ymd & (1<<5 - 1))
  	ym := ymd >> 5
  	month := int(ym % 13)
  	year := int(ym / 13)
  
  	hms := ymdhms & (1<<17 - 1)
  	second := int(hms & (1<<6 - 1))
  	minute := int((hms >> 6) & (1<<6 - 1))
  	hour := int(hms >> 12)
  	microsec := int(packed % (1 << 24))
  
  	t.Time = FromDate(year, month, day, hour, minute, second, microsec)
  
  	return nil
  }
docs: // FromPackedUint decodes Time from a packed uint64 value.