Is there a way to get system's Tz

[nooberfsh]

No description provided.

[quickdudley]

I'd be happy to do a PR to add this functionality to chrono-tz; especially since I also need it. However there's no platform-independent way to do this and I won't have access to a Windows environment for a few of days.

On Unix-like the best way is to try each of these and use the first one that gives you a valid timezone identifier

1. Check the TZ environment variable
2. If /etc/localtime is a symbolic link then check where it points: the path should be of the form {outer directory}/zoneinfo/{timezone identifier}
3. Search /usr/share/zoneinfo and /var/db/timezone/zoneinfo for a file which is the same as /etc/localtime

Windows has a C function called GetTimeZoneInformation in timezoneapi.h which is documented at https://docs.microsoft.com/en-us/windows/win32/api/timezoneapi/nf-timezoneapi-gettimezoneinformation

[astraw]

This is the raison d'etre of iana-time-zone. It's output can be parsed to make a chrono_tz::Tz like so:

let tz_str = iana_time_zone::get_timezone()?;
let tz: chrono_tz::Tz = tz_str.parse()?;

[djc]

I think that's a pretty good way to do it, so I'll close this for now.