在C ++中将星期几和星期几转换为日期时间

Question

If I have hour of the day and day of the week as 1am and Monday. How can I convert these into a datetime value in C++? thanks in advance.

Regards, Jack

Answer 1

may be this can help you:

boost.org

Answer 2

2am on Sunday occurs at least once a week (twice when switching to/from daylight saving!).

So you need the month and day in that month.

Answer 3

Time in standard C/C++ can be represented with std::tm

Structure holding a calendar date and time

std::tm tm;
tm.tm_wday = 1; // monday
tm.tm_hour = 1; // 1 am

How to get local time ?

#include <ctime>
...
time_t rawtime = time(&rawtime);
struct tm *tnow = localtime(&rawtime);

Maybe a simpler option would be to use C++11 time_point (must have compatible compiler)

system_clock::time_point now = system_clock::now();

then go back to a tm object

std::tm* tnow = localtime(now);

Time difference

struct tm diff = difftime(mktime(&tnow),mktime(&tm);