Implement parsing offset without colon

[spacemanspiff2007]

from whenever import OffsetDateTime

OffsetDateTime.parse_common_iso('2025-02-07T07:44:00.000+01:00')    # works
OffsetDateTime.parse_common_iso('2025-02-07T07:44:00.000+0100')     # without colon is doesn't

ValueError: Invalid format: '2025-02-07T07:44:00.000+0100'

I think the offset +0100 is pretty close to +01:00 and one of the more common formats so this seems to be worth supporting

[BurntSushi]

FWIW, Temporal does support this:

Temporal.Instant.from('2025-02-07T07:44:00.000+01:00').toString()
"2025-02-07T06:44:00Z"
Temporal.Instant.from('2025-02-07T07:44:00.000+0100').toString()
"2025-02-07T06:44:00Z" 

[ariebovenberg]

I think the offset +0100 is pretty close to +01:00 and one of the more common formats so this seems to be worth supporting

Fair point. It definitely is "common", and I agree most users will expect it to be parsed. My only concern is of course that we need to draw the line somewhere about what ISO is parsed, and what isn't.

yes yes slipperly slope but do we support...

• omitting seconds?
• two-digit offsets? (e.g. +05 instead of +05:00

@BurntSushi does Jiff draw the line at the same place as Temporal?

[BurntSushi]

Hmmm, do you know about Temporal's ISO 8601 grammar? That's what Jiff implements sans a few minor differences. The Temporal folks already did the (very) hard work of identifying the "good" parts of ISO 8601, while remaining compatible with RFC 3339 and RFC 9557. So I deferred strongly to them.

But yes, Jiff supports this too. These assertions pass:

use jiff::Timestamp;

fn main() -> anyhow::Result<()> {
    let ts: Timestamp = "2025-02-07T07:44:00.000+01:00".parse()?;
    assert_eq!(ts.to_string(), "2025-02-07T06:44:00Z");

    let ts: Timestamp = "2025-02-07T07:44:00.000+0100".parse()?;
    assert_eq!(ts.to_string(), "2025-02-07T06:44:00Z");

    Ok(())
}

[BurntSushi]

And see also tc39/proposal-temporal#2843