Module time_window 

The route time-window gate: the reference pipeline’s tenth check.

This is the Rust family’s port of guard_core/core/checks/implementations/time_window.py. A route’s time_restrictions dict (start, end, optional timezone, all "HH:MM" / IANA strings) admits requests only inside its window:

current local HH:MM in the zone (invalid zone -> UTC):
  start > end:   allowed when now >= start OR now <= end
                 (the window wraps midnight)
  otherwise:     allowed when start <= now <= end
missing start/end, or any evaluation error:  allowed
                                             (the reference's fail-open
                                             except arm, captured as
                                             normative by spec 03)

The comparisons are plain "HH:MM" string comparisons, exactly the reference’s strftime("%H:MM") ordering (lexicographic == chronological on the zero-padded form). Zone resolution uses the IANA database (ZoneInfo in the reference); a name the database does not know falls back to UTC, exactly the reference’s except arm around ZoneInfo.

Example

use guard_core_engine::time_window::{hhmm_in_zone, is_within, TimeWindow};
use chrono::TimeZone;

let window = TimeWindow { start: Some("09:00".into()), end: Some("17:00".into()), timezone: None };
assert!(is_within(&window, "09:00"));
assert!(is_within(&window, "12:30"));
assert!(!is_within(&window, "17:01"));

// A window past midnight wraps.
let night = TimeWindow { start: Some("22:00".into()), end: Some("06:00".into()), timezone: None };
assert!(is_within(&night, "23:30"));
assert!(is_within(&night, "05:59"));
assert!(!is_within(&night, "12:00"));

// The zone resolution: 12:00 UTC is 07:00 in New York (winter).
let utc = chrono::Utc.with_ymd_and_hms(2026, 1, 15, 12, 0, 0).unwrap();
assert_eq!(hhmm_in_zone(utc, Some("America/New_York")), "07:00");
// An unknown zone falls back to UTC.
assert_eq!(hhmm_in_zone(utc, Some("Mars/Olympus")), "12:00");

Structs

TimeWindow

One route’s time_restrictions: the window bounds and the IANA zone.

Constants

TIME_WINDOW_BLOCK_BODY

The block body the reference answers with.

TIME_WINDOW_BLOCK_STATUS

The block status the reference answers (create_error_response(403, default_message="Access not allowed at this time")).

TIME_WINDOW_CHECK_NAME

The check’s stable name (check_name).

Functions

hhmm_in_zone

The wall-clock "HH:MM" of now_utc observed in timezone.

is_within

The window decision against a current "HH:MM".