Date in VC++

[kathyayini]

I wants to check whether given date is valid or not or given date is greater/less than current date or i wants to add some date to given date.
Is there is any direct functions for all the above queries.
Waiting for the reply.

 

[qednick]

If you're using MFC then use the CTime and CTimeSpan classes - you can compare two date/times using the comparison operators '<' and '>', etc.

If you're using ANSI style C/C++, then you can use the [tt]difftime()[/tt] function to get the time difference between two [tt]time_t[/tt] structures:

[tt]time_t nowTime;
time(&nowTime);
gmtime(&nowTime); // get the current GMT time

// assume 'oldTime' is some older time variable
// already initialized
double diff = difftime(nowTime,oldTime);[/tt]

actually, a time_t value is simply the number of seconds since jan 1st, 1970. You can get the difference between two time_t values in seconds like this:

[tt]unsigned diff = (unsigned)t1-(unsigned)t2;[/tt]

where t1 is a later time than t2. Also you can compare them:

[tt]if ((unsigned)t1 > (unsigned)t2) {}[/tt]

[sup]programmer (prog'ram'er), n A hot-headed, anorak wearing, pimple-faced computer geek.[/sup]​

 

[kathyayini]

earlier i was using CTime but year must be with in 1970–2038 so i dropped the idea of using CTime and CTimeSpan. and difftime returns double-precision floating-point number.
but i want date/month/year difference.

 

[mathu]

for getting the current date and time u can use the function
GetSystemTime(&sysTime);
sysTime is of type SYSTEMTIME structure.

GetSystemTime() fills the SYSTEMTIME structure with the
current date and time.

Now u can use the individual elements of this structure to
compare the current date with the given date.

Hope this helps u.

 

[qednick]

COleDateTime is similar to CTime but has a much larger time range. However, I'm not too sure if the CTimeSpan class will work past 1970 - you could give it a shot.

[sup]programmer (prog'ram'er), n A hot-headed, anorak wearing, pimple-faced computer geek.[/sup]​

 

[mathu]

k