Trigger rules based on local business hours, timezones, and day-of-week context.

Veto YAML rules support two time-window operators for local deterministic checks:

within_hours: matches when the current call time is inside a configured window
outside_hours: matches when the current call time is outside a configured window

Both operators are evaluated in-process (no network calls) and use timezone-aware conversion.

Required value shape

Use these operators with field: context.time and an object value:

conditions:
  - field: context.time
    operator: outside_hours
    value:
      start: "09:00"              # HH:MM (24-hour)
      end: "17:00"                # HH:MM (24-hour)
      timezone: "America/New_York" # IANA timezone
      days: ["mon", "tue", "wed", "thu", "fri"] # Optional

days is optional:

omitted: window applies every day
provided: only listed days are in scope (mon, tue, wed, thu, fri, sat, sun)

Context fields

Time conditions use built-in runtime context fields:

context.time: current timestamp (ISO string)
context.day_of_week: current lowercase day abbreviation (sun..sat)

You can combine context.day_of_week with existing operators like in, not_in, equals, and not_equals.

Examples

Block calls outside weekday business hours

rules:
  - id: block-off-hours
    name: Block outside business hours
    action: block
    tools: [wire_transfer]
    conditions:
      - field: context.time
        operator: outside_hours
        value:
          start: "09:00"
          end: "17:00"
          timezone: "America/New_York"
          days: ["mon", "tue", "wed", "thu", "fri"]

Allow only during a timezone-specific window

rules:
  - id: allow-work-hours
    name: Allow in work hours
    action: allow
    tools: [wire_transfer]
    conditions:
      - field: context.time
        operator: within_hours
        value:
          start: "09:00"
          end: "17:00"
          timezone: "America/Los_Angeles"

Weekend lockdown with `context.day_of_week`

rules:
  - id: weekend-lockdown
    name: Restrict production deploys on weekends
    action: block
    tools: [deploy]
    conditions:
      - field: context.day_of_week
        operator: in
        value: ["sat", "sun"]

Overnight windows (`start > end`)

When start is later than end, Veto treats the window as crossing midnight.

rules:
  - id: overnight-maintenance-window
    name: Allow restarts overnight
    action: allow
    tools: [restart_service]
    conditions:
      - field: context.time
        operator: within_hours
        value:
          start: "22:00"
          end: "06:00"
          timezone: "UTC"

Behavior details

Timezone conversion is done with Intl.DateTimeFormat in TypeScript and zoneinfo in Python.
Invalid timezone values do not throw; the condition simply evaluates to false.
If a days filter is set, out-of-scope days evaluate to false for both within_hours and outside_hours.
For overnight windows with days, early-morning times are evaluated against the previous day (window start day).

For the full rule schema and operator table, see YAML Rule Format.

Time-Based Conditions