Date

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Summary

This is actually several separate C++11/C++14/C++17 libraries:

1. "date.h" is a header-only library which builds upon <chrono>. It adds some new duration types, and new time_point types. It also adds "field" types such as year_month_day which is a struct {year, month, day}. And it provides convenient means to convert between the "field" types and the time_point types.

   • Documentation: http://howardhinnant.github.io/date/date.html
   • Video: https://www.youtube.com/watch?v=tzyGjOm8AKo
   • Slides: http://schd.ws/hosted_files/cppcon2015/43/hinnant_dates.pdf

2. "tz.h" / "tz.cpp" are a timezone library built on top of the "date.h" library. This timezone library is a complete parser of the IANA timezone database. It provides for an easy way to access all of the data in this database, using the types from "date.h" and <chrono>. The IANA database also includes data on leap seconds, and this library provides utilities to compute with that information as well.

   • Documentation: http://howardhinnant.github.io/date/tz.html
   • Video: https://www.youtube.com/watch?v=Vwd3pduVGKY
   • Slides: http://schd.ws/hosted_files/cppcon2016/0f/Welcome%20To%20The%20Time%20Zone%20-%20Howard%20Hinnant%20-%20CppCon%202016.pdf

3. "iso_week.h" is a header-only library built on top of the "date.h" library which implements the ISO week date calendar.

   • Documentation: http://howardhinnant.github.io/date/iso_week.html

4. "julian.h" is a header-only library built on top of the "date.h" library which implements a proleptic Julian calendar which is fully interoperable with everything above.

   • Documentation: http://howardhinnant.github.io/date/julian.html

5. "islamic.h" is a header-only library built on top of the "date.h" library which implements a proleptic Islamic calendar which is fully interoperable with everything above.

   • Documentation: http://howardhinnant.github.io/date/islamic.html

Standardization

Slightly modified versions of "date.h" and "tz.h" were voted into the C++20 working draft at the Jacksonville FL meeting on 2018-03-17:

• http://howardhinnant.github.io/date/d0355r7.html

Build & Test

You can optionally build using CMake. Here is a guide of how to build and test using the CMake Makefile generator.

mkdir build
cd build
cmake ../
cmake --build . --target testit # Consider '-- -j4' for multithreading

Projects using this library

• www.safe.com
• www.webtoolkit.eu/wt
• https://github.com/ViewTouch/viewtouch
• https://routinghub.com
• https://github.com/valhalla

If you would like your project (or product) on this list, just let me know.