Windows C++ / Time Bomb

Code

#include <ctime>
#include <iostream>
#include <string>
#include <sstream>

const double time_attack_in_days = 1.0;

using namespace std;

time_t time_when_compiled()
{
    string datestr = __DATE__;
    string timestr = __TIME__;
    istringstream iss_date(datestr);
    string str_month;
    int day;
    int year;
    iss_date >> str_month >> day >> year;

    int month;
    if      (str_month == "Jan") month = 1;
    else if (str_month == "Feb") month = 2;
    else if (str_month == "Mar") month = 3;
    else if (str_month == "Apr") month = 4;
    else if (str_month == "May") month = 5;
    else if (str_month == "Jun") month = 6;
    else if (str_month == "Jul") month = 7;
    else if (str_month == "Aug") month = 8;
    else if (str_month == "Sep") month = 9;
    else if (str_month == "Oct") month = 10;
    else if (str_month == "Nov") month = 11;
    else if (str_month == "Dec") month = 12;
    else exit(-1);

    for(string::size_type pos = timestr.find(':'); pos != string::npos; pos = timestr.find(':', pos))
    {
    	timestr[pos] = ' ';
    }

    istringstream iss_time(timestr);
    int hour, min, sec;
    iss_time >> hour >> min >> sec;
    tm t = {0};
    t.tm_mon = month - 1;
    t.tm_mday = day;
    t.tm_year = year - 1900;
    t.tm_hour = hour;
    t.tm_min = min;
    t.tm_sec = sec;

    return mktime(&t);
}

int main()
{
    time_t current_time = time(NULL);
    time_t build_time = time_when_compiled();

    double diff_time = difftime(current_time, build_time);
    const double time_to_wait = time_attack_in_days * 24.0 * 60.0 * 60.0;

    // trigger the time of execution
    if(diff_time > time_to_wait)
    {
        cout << "Time of attack!" << endl;
        exit(-1);
    }
    else
    {
        cout << "Time in second before running the attack: " << time_to_wait << endl;
    }

    return 0;
}