Looks like date.h does not work with Ubuntu's system TZ DB (Build Manual_TZ_DB=ON + install string = "/usr/share/zoneinfo" on Ubuntu)

[nirvikalpa7]

Hi guys! I tried to use Ubuntu system TZ DB for an app on date.h (built without curl support - Manual_TZ_DB=ON)
But after start my simple app I see a coredump and error message "Can not find version for TZ DB"
I tried to copy the version file from downloaded IANA TZ DB to Linux path: "/usr/share/zoneinfo"
but after that I had a coredump anyway with an error message: Can not find TimeZone - America/New_York (my app uses it just as an example).

So the question: Can we use somehow system Ubuntu's TZ DB instead of downloading TZ DB from IANA web site? or are they incompatible? Thank you for your time and reply anyway.

[nirvikalpa7]

Probably I should use USE_SYSTEM_TZ_DB option for build? It must help?

[HowardHinnant]

If you have gcc-14 and C++20 available, using std::chrono should be your first choice. Otherwise I do not recommend using CMake unless you are an expert at it.

Here are the recommended build instructions: https://howardhinnant.github.io/date/tz.html#Installation