Question

I am trying to create a Date header for an email.

The format is as follows:

DayOfWeek, Day ShortMonth Year Hours:Minutes:Seconds Offset (TimeZone)

So an example would be:

Fri, 19 Mar 2010 11:44:09 -0700 (PDT)

Its the TimeZone part (PDT in the example) that I’m trying to get. I realize that this will be different across systems, but I’d like a solution for all of them.

Thanks!

Answer 1

You are looking for %Z in strftime().

For example:

#include <stdio.h>
#include <time.h>

int main()
{
    char buf[16];
    time_t t = time(0);

    strftime(buf, sizeof(buf), "%Z", localtime(&t));
    printf("%s\n", buf);

    return 0;
}

And it’s C89, AFAIR (which means it’s very portable).

Snippet from the C99 standard:

%Z is replaced by the locale’s time zone name or abbreviation, or by no characters if no time zone is determinable. [tm_isdst]

Sadly, as we noticed not every system gives reasonable values for it…