[gnome-db] check gdatime and gdatimestamp validity

i wrote these two functions to validate gdatime and gdatimestamp

/**
  * gda_time_valid
  * @time: a #GdaTime value to check if it is valid
  *
  * Returns: #TRUE if #GdaTime is valid; FALSE otherwise.
  */
gboolean
gda_time_valid (const GdaTime *time)
{
	g_return_val_if_fail (time != NULL, FALSE);

	if (time->hour < 0 || time->hour > 24
	    || time->minute < 0 || time->minute > 59
	    || time->second < 0 || time->second > 59)
		return FALSE;
	/* TODO i don't undestand how timestamp->timezone work */
	/* TODO i don't know how timestamp->fraction work */

	return TRUE;
}

/**
  * gda_timestamp_valid
  * @timestamp: a #GdaTimestamp value to check if it is valid
  *
  * Returns: #TRUE if #GdaTimestamp is valid; FALSE otherwise.
  */
gboolean
gda_timestamp_valid (const GdaTimestamp *timestamp)
{
	g_return_val_if_fail (timestamp != NULL, FALSE);

	GDate *gdate;

	/* check the date part */
	gdate = g_date_new_dmy ((GDateDay)timestamp->day,  
(GDateMonth)timestamp->month, (GDateYear)timestamp->year);
	if (gdate == NULL)
		return FALSE;

	/* check the time part */
	if (timestamp->hour < 0 || timestamp->hour > 24
	    || timestamp->minute < 0 || timestamp->minute > 59
	    || timestamp->second < 0 || timestamp->second > 59)
		return FALSE;
	/* TODO i don't undestand how timestamp->timezone work */
	/* TODO i don't know how timestamp->fraction work */

	return TRUE;
}

if you think that it can be useful inside libgda, fell free to use  
them (i think that libgda functions  operating on gdatime and gdatime  
(ex. gda_value_get_timestamp) must before validate the value)