Function parse_iso_timestamp 

pub fn parse_iso_timestamp(ts: &str) -> i64

Parses an ISO-8601 / RFC 3339 timestamp into Unix milliseconds.

RFC 3339 is tried first (the common case, with timezone offset or Z), then a small set of explicit UTC fallback patterns covering 3-digit, arbitrary-precision, and zero-fraction sub-seconds. Surrounding whitespace is not tolerated.

Returns 0 for an empty string or any input that matches none of the accepted formats; callers treat 0 as “unknown time” rather than the Unix epoch.

Examples

use vct_core::utils::parse_iso_timestamp;

assert_eq!(parse_iso_timestamp("1970-01-01T00:00:01Z"), 1_000);
assert_eq!(parse_iso_timestamp(""), 0);
assert_eq!(parse_iso_timestamp("not a timestamp"), 0);