Get time zone offset from time zone name in C++

Question

I need to get time zone offset from a time zone name string expressed exactly like this "Pacific/Auckland". I know that boost::date_time would do the job, but I need to do it without that. Manipulations with TZ variable are also not allowed. Anyone have idea how to accomplish this task in such a way?

You need to find, build, buy, borrow, or steal a database of timezone names. Try the find option first. Perhaps there's one on your linux machine. — n. m. could be an AI, Oct 23 '15 at 07:53
@n.m thanks :))) I will try. Actually there is public timezone DB exists for example here https://www.iana.org/time-zones — ivan.ukr, Oct 23 '15 at 07:59
@ivan.ukr:- Did you check this: [How to get the current time zone?](http://stackoverflow.com/questions/2136970/how-to-get-the-current-time-zone) — Rahul Tripathi, Oct 23 '15 at 07:59
@Rahul Tripathi: I need a different time zone, not current. With current time zone everything is very clear. — ivan.ukr, Oct 23 '15 at 08:01
@Rahul Tripathi: Doesn't work for me. Uses either boost or TZ variable manipulation. — ivan.ukr, Oct 23 '15 at 08:07

score 2 · Answer 1 · answered Mar 22 '22 at 14:19

I know this is an old question, but I just had to write the code list the known timezones, so I'm sharing it here.

#include <date/tz.h>

const date::tzdb & tzdb = date::get_tzdb();
for (const date::time_zone & tz: tzdb.zones) {
    cout << "TZ: " << tz.name() << endl;
}

This uses Howard Hinnants Date Library, and you'll need to compile in the tz.cpp file and have a path to the includes.

With C++20, the library is part of the standard, but I'm still on C++17.

Thank you. I also noticed this library. – ivan.ukr Mar 22 '22 at 17:40 — ivan.ukr, Mar 22 '22 at 17:40

score 1 · Accepted Answer · answered Oct 23 '15 at 07:54

1

Take a look at Howard Hinnant's parser for the Time Zone Database. He also provides a very good date/time library.

answered Oct 23 '15 at 07:54

Jens

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Thanks, I will take a look. This may be really what I am looking for. – ivan.ukr Oct 23 '15 at 07:57
Yes, this is definitely what I need. – ivan.ukr Oct 23 '15 at 08:45

Get time zone offset from time zone name in C++

2 Answers2