Invalid datetime format for korean(ko_KR)

[scarf005]

Summary

South korea uses Year-Month-Day date format like rest of east asia. however, it's invalidly rendered as Month-Day-Year with %c.

$ date '+%c
2023년 03월 09일 (목) 오전 11시 59분 40초
$ cargo run # chrono +%c
03/09/23 (목) 11:59:36 오전

To reproduce

(tested in 0.4.23)

use chrono::{Local, Locale};

fn main() {
    let time = Local::now();
    let display = |fmt: &str| {
        let localized = time.format_localized(fmt, Locale::ko_KR);
        println!("{fmt}: {localized}");
    };
    display("%c");
    display("%r");
}

%c: 03/09/23 (목) 11:59:36 오전
%r: 11:59:36 오전
 ~/repo   …  locale  date '+%c'
2023년 03월 09일 (목) 오전 11시 59분 40초
 ~/repo   …  locale  date '+%r'
오전 11시 59분 42초

[djc]

I think you'll need to file an issue against https://github.com/cecton/pure-rust-locales.

[scarf005]

@djc i've looked at pure-rust-locales, it defines korean datetime format as "%x (%a) %r".

#[test]
fn locale_match_ko_kr() {
    let locale = "ko_KR".try_into().unwrap();
    let d_fmt = pure_rust_locales::locale_match!(locale => LC_TIME::D_FMT);
    assert_eq!(d_fmt, "%Y년 %m월 %d일");

    let d_t_fmt = pure_rust_locales::locale_match!(locale => LC_TIME::D_T_FMT);
    assert_eq!(d_t_fmt, "%x (%a) %r");
}

i've modified strftime.rs to debug how d_t_fmt was used as following:

    pub fn new_with_locale(s: &'a str, locale: Locale) -> StrftimeItems<'a> {
		// ...
        let d_t_fmt = StrftimeItems::new(locales::d_t_fmt(locale)).collect();
        println!("locales: {:?}", locales::d_t_fmt(locale));
        println!("d_t_fmt: {:?}", d_t_fmt);
		// ...
    }
/*
locales: "%x (%a) %r"
d_t_fmt: [Numeric(Month, Zero), Literal("/"), Numeric(Day, Zero), Literal("/"), Numeric(YearMod100, Zero), Space(" "), Literal("("), Fixed(ShortWeekdayName), Literal(")"), Space(" "), Numeric(Hour12, Zero), Literal(":"), Numeric(Minute, Zero), Literal(":"), Numeric(Second, Zero), Space(" "), Fixed(UpperAmPm)]
thread 'format::strftime::test_strftime_localized_korean' panicked at 'assertion failed: `(left == right)`
*/

does parsing %x take locale into account? because

assert_eq!(dt.format_localized("%x", Locale::ko_KR).to_string(), "2001년 07월 08일");

will pass.

[djc]

Maybe it doesn't? Unfortunately I don't have much time to investigate right now. Would be happy to review a PR if you're able to figure it out!

[scarf005]

chrono/src/format/strftime.rs

Lines 259 to 269 in 43579a5

	fn with_remainer(s: &'a str) -> StrftimeItems<'a> {
	StrftimeItems {
	remainder: s,
	recons: Vec::new(),
	d_fmt: D_FMT.to_vec(),
	d_t_fmt: D_T_FMT.to_vec(),
	t_fmt: T_FMT.to_vec(),
	}
	}
	}

alright, i'm investigating, and i think i found the cause: with_remainer does not take d_fmt into account. d_t_fmt in ko_KR depends on d_fmt, so it was failing.

for verification, when i changed with_remainers into this, test passes:

    #[cfg(feature = "unstable-locales")]
    fn with_remainer(s: &'a str) -> StrftimeItems<'a> {
        println!("with remainer s: {:?}", s);
        StrftimeItems {
            remainder: s,
            recons: Vec::new(),
            // d_fmt: D_FMT.to_vec(),
            d_fmt: StrftimeItems::new(locales::d_fmt(Locale::ko_KR)).collect(),
            d_t_fmt: D_T_FMT.to_vec(),
            t_fmt: T_FMT.to_vec(),
        }
    }

[pitdicker]

Fixed in #1165.