Time can't be roundtrip formatted/parsed using ISO 8601 format

[Anfid]

When using ISO 8601 formatter, time is formatted having 'T' prefix, for example "T00:23:23.078374000". ISO 8691 parser, however, only allows T if the date component is present. I was able to trace it down to this bit of code:

time/time/src/parsing/iso8601.rs

Line 121 in 037af66

input = ascii_char::<b'T'>(input)

Unfortunately I don't have an access to the full original ISO spec, but at least the comment in the linked function and the Wikipedia article on ISO both state that T component CAN be ommitted (as opposed to MUST) in non-ambiguous scenarios. So from my understanding, T prefix should be allowed for times even without dates, at least with later standard iterations.

Example code to reproduce:

main.rs

fn main() {
    let now = time::OffsetDateTime::now_utc();
    let now_time = now.time();
    let now_time_str = now_time
        .format(&time::format_description::well_known::Iso8601::TIME)
        .unwrap();
    let parsed = time::Time::parse(
        &now_time_str,
        &time::format_description::well_known::Iso8601::TIME,
    )
    .unwrap(); // Currently fails here
    assert_eq!(now_time, parsed);
}

Cargo.toml

[package]
name = "timetest"
version = "0.1.0"
edition = "2024"

[dependencies]
time = { version = "0.3.44", features = ["formatting", "parsing"] }

The fix seems straightforward enough, so I could probably try and work on it myself. Let me know if I should.