CODEWITHSUNDEEP
c++datetimetimetimespan
Aleksandre Sukhitashvili
Aleksandre Sukhitashvili

Reputation: 132

How to subtract time from date

Is there standard c++ time class which has methods to subtract dates for example: I want to subtract 10 minutes from date like this(Jan 1 Mon 2014 00:05) and get date like that(Dec 31 Sun 2013 23:55)

It would be awesome if there was such function for "struct tm" type

Upvotes: 1

Views: 1264

Answers (3)

Bur0k
Bur0k

Reputation: 136

If you can use C++11 you can substract and add dates easy:

#include <iostream>
#include <chrono>
#include <ctime>
#include <ratio>
using namespace std;

int main ()
{
  chrono::system_clock::time_point today = chrono::system_clock::now();
  chrono::system_clock::duration dtn (chrono::duration<int,ratio<60,1>>(10));

  time_t t = chrono::system_clock::to_time_t(today-dtn);
  cout << ctime(&t) << endl;

  return 0;
}

Upvotes: 0

stefaanv
stefaanv

Reputation: 14392

cppreference shows enough functions (mktime, localtime) to convert struct tm with time_t. Calculations are obvious with time_t because it is an integral type traditionally representing the number of seconds since newyear 1970.

Upvotes: 2

Dakorn
Dakorn

Reputation: 903

i don't know if there are any method for struct tm but I think you should read about chrono available in C++11. Link

Upvotes: 0

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