Scheduling Tasks

Ordinaut provides a flexible and powerful scheduling system that supports several methods for defining when a task should run. You can choose the method that best fits your needs, from simple one-time executions to complex, calendar-aware recurring schedules.

When creating a task, you specify the scheduling method using the schedule_kind field and provide the corresponding expression in schedule_expr.

RRULE Scheduling

For the most complex, calendar-aware scheduling, Ordinaut uses the powerful RFC 5545 Recurrence Rule (RRULE) standard. This allows you to define sophisticated schedules that go far beyond what traditional cron expressions can support.

Set schedule_kind to rrule to use this method.

Common RRULE Examples

Use Case	RRULE Expression
Every weekday at 8:30 AM	`FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR;BYHOUR=8;BYMINUTE=30`
Every other Monday at 10:00 AM	`FREQ=WEEKLY;INTERVAL=2;BYDAY=MO;BYHOUR=10`
The last Friday of every month at 5:00 PM	`FREQ=MONTHLY;BYDAY=FR;BYSETPOS=-1;BYHOUR=17`
The first day of every quarter at 9:00 AM	`FREQ=MONTHLY;INTERVAL=3;BYMONTHDAY=1;BYHOUR=9`
Annually on June 15th	`FREQ=YEARLY;BYMONTH=6;BYMONTHDAY=15`
Twice a day (9 AM and 6 PM)	`FREQ=DAILY;BYHOUR=9,18`

Key RRULE Components

An RRULE string is a semicolon-separated list of properties like FREQ, INTERVAL, BYDAY, BYMONTH, BYHOUR, etc.

Timezones and DST

RRULE processing in Ordinaut is fully timezone-aware. It is critical to provide a valid timezone name (e.g., Europe/Chisinau) in your task definition to ensure schedules handle Daylight Saving Time (DST) transitions correctly.

Cron Scheduling

For traditional, time-based scheduling, Ordinaut supports standard 5-field cron expressions.

Set schedule_kind to cron to use this method.

Cron Expression Format

The format is a string with five fields separated by spaces:

* * * * *

Minute (0-59)
Hour (0-23)
Day of Month (1-31)
Month (1-12)
Day of Week (0-6, where Sunday is 0 and 6, or use names like SUN, MON)

Example Cron Task

{
  "title": "Hourly System Cleanup",
  "description": "Run a cleanup script at the beginning of every hour.",
  "schedule_kind": "cron",
  "schedule_expr": "0 * * * *",
  "timezone": "UTC",
  "payload": { ... },
  "created_by": "..."
}

One-Time Scheduling

To schedule a task to run exactly once at a specific time in the future, you can use the once schedule kind.

Set schedule_kind to once to use this method.

`once` Expression Format

The schedule_expr for a one-time task must be a timestamp in ISO 8601 format.

Example One-Time Task

{
  "title": "Deploy New Feature",
  "description": "Trigger the deployment pipeline at a specific time.",
  "schedule_kind": "once",
  "schedule_expr": "2025-12-25T09:00:00+02:00",
  "timezone": "Europe/Chisinau",
  "payload": { ... },
  "created_by": "..."
}

This task will execute a single time on Christmas Day 2025 at 9:00 AM in the Chișinău timezone.