// simulates legacy C code
#include <stdio.h>
typedef union
{
   int i;
   struct {
      unsigned char d;
      unsigned char m;
      unsigned short y;
   } s;
} MDATUM;
static MDATUM MDatumSetDatum(int d, int m, int y)
{
   MDATUM md={0};
   md.s.d=d; md.s.m=m; md.s.y=y;
   return md;
}

const char* MDatumSprintf(char *buff, MDATUM md)
{
   static char sbuff[20];
   if (!buff) buff=sbuff;

   sprintf(buff, "%02d.%02d.%04d", md.s.d, md.s.m, md.s.y);
   return buff;
}

// new code, please comment

#include <boost/date_time/gregorian/gregorian.hpp>
#include <boost/date_time/local_time/local_time.hpp>

#include <iostream>
#include <string>
using namespace std;
using boost::gregorian::date;

using namespace boost::gregorian;
using namespace boost::posix_time;
using namespace boost::local_time;

#define ID_INP_NORMDAT "%d.%m.%Y"

static MDATUM date_to_mdatum(const date &d)
{
   return MDatumSetDatum(d.day(), d.month(), d.year());
}

static MDATUM parse_date(const char * const sDate, const char * const sFormat)
{
   string s(sDate);
   std::stringstream ss(s);
   date_input_facet* facet(new date_input_facet(sFormat));
   ss.imbue(locale(ss.getloc(), facet));
   date d(2000,1,1);
   ss >> d;
   return date_to_mdatum(d);
}

int main(int, char **)
{
   try
   {
      MDATUM md = parse_date("02.05.1974", ID_INP_NORMDAT);
      cerr << "read: " << MDatumSprintf(NULL, md) << endl;
   }
   catch (const exception &e)
   {
      cerr << "Exception: " << e.what() << endl;
   }
   return 0;
}