'CEST' or 'CET' timezone silently treated as UTC

[Jajcus]

When 'CEST' or 'CET' time zone name is used in parsed string it is treated as UTC.

It should either be properly interpreted as Central European (Summer) Time, or an error should be reported or, at least, it should be treated as no time zone provided (so the default from parse_with_timezone() can be used). Current behaviour is quite unexpected.

Test code:

use chrono::Local;
use dateparser::{parse, parse_with_timezone};

pub fn main() {
    check_date("2024-07-29 12:00:00 +02:00");
    check_date("2024-07-29 12:00:00 CEST");
    check_date("2024-07-29 12:00:00 CET");
    check_date("2024-07-29 12:00:00 PST");

    check_local_date("2024-07-29 12:00:00");
    check_local_date("2024-07-29 12:00:00 +02:00");
    check_local_date("2024-07-29 12:00:00 CEST");
}

fn check_date(value: &str) {
    println!("'{}' is: {}", value, parse(value).unwrap())
}

fn check_local_date(value: &str) {
    println!(
        "'{}' is: {} (with local timezone)",
        value,
        parse_with_timezone(value, &Local).unwrap()
    )
}

Output:

'2024-07-29 12:00:00 +02:00' is: 2024-07-29 10:00:00 UTC
'2024-07-29 12:00:00 CEST' is: 2024-07-29 12:00:00 UTC
'2024-07-29 12:00:00 CET' is: 2024-07-29 12:00:00 UTC
'2024-07-29 12:00:00 PST' is: 2024-07-29 20:00:00 UTC
'2024-07-29 12:00:00' is: 2024-07-29 10:00:00 UTC (with local timezone)
'2024-07-29 12:00:00 +02:00' is: 2024-07-29 10:00:00 UTC (with local timezone)
'2024-07-29 12:00:00 CEST' is: 2024-07-29 12:00:00 UTC (with local timezone)

The string is properly interpreted by the date command:

$ date --date="2024-07-29 12:00:00 CEST"
Mon 29 Jul 12:00:00 CEST 2024