kennytm / tzfile Goto Github PK

this would enable more cases like accepting user provided timezone identifiers

Chrono's Serialize implementation uses Debug formatting for Serialize, and assumes that it will produce valid RFC 3339: https://docs.rs/chrono/0.4.19/src/chrono/datetime.rs.html#2066
https://docs.rs/chrono/0.4.19/src/chrono/datetime.rs.html#720

ArcTz's offset prints the time zone's name in Debug, not the offset, so DateTime serializes into an incorrect format.

For example:

use chrono::{DateTime, NaiveDate, TimeZone};
use serde::Serialize;
use tzfile::ArcTz;

#[derive(Debug, Serialize)]
pub struct Foo {
    pub date: DateTime<ArcTz>,
}

fn main() {
    let tz = ArcTz::named("Europe/Budapest").unwrap();
    let dt = tz.from_utc_datetime(&NaiveDate::from_ymd(2021, 3, 11).and_hms(17, 49, 32));
    println!("{:?}", dt.offset());
    let foo = Foo { date: dt };
    let j = serde_json::to_string(&foo).unwrap();
    println!("{}", j);
}

This prints {"date":"2021-03-11T18:49:32CET"}, which isn't valid RFC3339.

It would be nice to mirror the functionality from chrono_tz and, for example, make tzfile::Tz serializable.

Windows user here, is there a chance to use it?

According to https://www.freedesktop.org/software/systemd/man/localtime.html, if /etc/localtime is missing, the default UTC time zone should be used.
Currently, Tz::local() returns a No such file or directory error. It would be nice if Tz::local() defaults to parsing /usr/share/zoneinfo/UTC if /etc/localtime is not found.

Tz::named always loads its time zones from /usr/share/zoneinfo/, even if TZDIR is set. From what I can tell, glibc respects this variable.

This would be useful since NixOS uses a nonstandard time zone directory location (/etc/zoneinfo/ or /etc/static/zoneinfo/) which this library currently can't find.