int Field::store_timestamp(my_time_t ts, ulong sec_part)
{
  MYSQL_TIME ltime;
  get_thd()->timestamp_to_TIME(&ltime, ts, sec_part, 0);
  return store_time_dec(&ltime, decimals());
}
int Field::store_timestamp(my_time_t ts, ulong sec_part)
{
  MYSQL_TIME ltime;
  get_thd()->timestamp_to_TIME(&ltime, ts, sec_part, 0);
  return store_time_dec(&ltime, decimals());
}