It's seems faster than the algorithm now in use. The execute file and project file please see the attach. DateValidate cost : 00:00:17.765546 boost_date_validate cost : 00:00:50.232232 Below is cpp source of the algorithm and test ---------------------------------------------------------------------------------------- #include <boost/lexical_cast.hpp> #include <stdio.h> #include <string.h> #include <stdlib.h> #include <iostream> #include <string> #include <boost/date_time/posix_time/posix_time.hpp> using namespace std; using namespace boost; using namespace boost::posix_time; using namespace boost::gregorian; int create_date() { int year=rand() %200+1900; int month=rand() %20; int day=rand() %40; return year*10000+month*100+day; } void date_validate(int date) { static int daysOfMonth[] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 }; int monthDay = date % 10000; if (monthDay >= 1300) throw bad_month(); if (monthDay > 1231) throw bad_day_of_month(); if (monthDay == 229) { int year = date / 10000; if ( (year % 4) != 0) throw bad_day_of_month(); if (year %100 == 0 && year % 16 != 0) throw bad_day_of_month(); } int month = monthDay / 100; int day = monthDay % 100; if (! (day > 0 && day <= daysOfMonth[month]) ) throw bad_day_of_month(); } bool DateValidate (string date) { try { date_validate( lexical_cast<int> (date)); return true; } catch (...) { return false; } } bool boost_date_validate (string date) { try { from_undelimited_string (date); return true; } catch (...) { return false; } } int main() { int n=1000000; ptime createDateBegin (microsec_clock::local_time() ); for (int i=0;i<n;i++) { int r=create_date(); string t=lexical_cast<string> (r); } ptime createDateEnd (microsec_clock::local_time() ); time_duration createTime=createDateEnd-createDateBegin; cout<<"create_date cost : "<<createDateEnd-createDateBegin<<"\n"; createDateBegin=microsec_clock::local_time(); for (int i=0;i<n;i++) { int r=create_date(); string t=lexical_cast<string> (r); DateValidate (t); } createDateEnd=microsec_clock::local_time(); cout<<"DateValidate cost : "<<createDateEnd-createDateBegin-createTime<<"\n"; createDateBegin=microsec_clock::local_time(); for (int i=0;i<n;i++) { int r=create_date(); string t=lexical_cast<string> (r); boost_date_validate (t); } createDateEnd=microsec_clock::local_time(); cout<<"boost_date_validate cost : "<<createDateEnd-createDateBegin-createTime<<"\n"; cin.get(); return 0; }