--- title: "Introduction to Cron Expressions" slug: "introduction-to-cron-expressions" updated: 2025-09-26T04:18:42Z published: 2025-09-26T04:18:42Z canonical: "docs.unqork.io/introduction-to-cron-expressions" --- > ## Documentation Index > Fetch the complete documentation index at: https://docs.unqork.io/llms.txt > Use this file to discover all available pages before exploring further. # Introduction to Cron Expressions ## Overview **Cron expressions** are used for scheduling and automating tasks to run at a specific time/date. Cron expressions consist of five to six subexpressions that describe the details of the schedule. These subexpressions might be further modified or replaced by specific special characters. Unqork supports the use of Cron expressions to schedule [Timer Start](/v1/docs/timer-start-node) and [Timer](/v1/docs/timer-node) node tasks in Workflow. Schedules in Unqork use the UTC **(Cordinated Universal Time)** time zone. ## Formatting Cron Expressions in Unqork Cron expressions in Unqork function similarly to how it is used for other services. A set of values called subexpressions dictate the date and time a task is performed. In Unqork, the Workflow Timer Start and Timer Nodes support Cron expressions. > [!TIP] > To learn more about Timer Start and Timer nodes, visit our [Timer Start Node](/v1/docs/timer-start-node) and [Timer Node](https://docs.unqork.io/Content/B01-WorkflowEditor-Nodes/B01026-Timer_Node.htm) articles. The format for Cron expressions in the Unqork Designer Platform is: ```plaintext *    *    *    *    *    * ┬    ┬    ┬    ┬    ┬    ┬ │    │    │    │    │    | │    │    │    │    │    └ Day-of-week │    │    │    │    └───── Month │    │    │    └────────── Day-of-month │    │    └─────────────── Hour │    └──────────────────── Minute └───────────────────────── Second ``` The requirements, subexpression values, and special characters Unqork supports for Cron are: | **Subexpression Field** | Required | Values | Supported Special Characters | | --- | --- | --- | --- | | **Second** | Optional | 0-59 (in seconds) | , - * / | | **Minute** | Required | 0-59 (in minutes) | , - * / | | **Hour** | Required | 0-23 (in a 24 hour period) | , - * / | | **Day-of-month** | Required | 0-31 | , - * ? / L | | **Month** | Required | 1-12 | , - * / | | **Day-of-week** | Required | 0-6 (0 is Sunday, 6 is Saturday) | , - * ? / L # | The function for each special character is: | **Special Character** | Meaning | Description | Example | | --- | --- | --- | --- | | **,** | Multiple Values | Allows multiple values. | Inserting `12,14, 6`in the field indicates the hours 12pm, 2pm, and 4 pm. | | **-** | Range | Represents a continuous range of values. | Using `12-14` in the field indicates the hours 12pm, 1pm, and 2pm. | | ***** | All | The schedule runs for every time unit. | Placing a `*` in the field indicates the schedule to run every minute. | | **/** | Increment | The amount by which to increment the values of a field. | A expression of `*/10` indicates the minutes 0, 10, 20, 30, etc. | | **?** | Any | Representing an arbitrary value. | A `?` in the field does not use the day-of-month for deciding the schedule. | | **L** | Last | Last occurrence of this weekday for the month in progress. | The expression `0 0 * * * 6L` indicates the schedule runs on the last Saturday of the month at midnight. | | **#** | Nth Weekday | Specifies the Nth weekday of the month. | The value of `0#2` in the day-of-week field means the second Sunday of the month (Day 0 = Sunday and #2 = the 2nd one in the month). > [!NOTE] > If you use the '#' character, you can define only one expression in the day-of-week field. For example, `3#1,6#3` is not valid because it is interpreted as two expressions. | ## Using Cron Expressions With Timer and Timer Start Nodes in Workflow Unqork Designer Platform Workflow Timer and Timer Start nodes support the use of Cron. To build a Cron expression in Unqork, specify the values for each subexpression in a single line, with spaces between each subexpression. For example, to schedule a task that is performed every two hours, every day, your expression looks like this: `0 0 0/2 * * ?` To use Cron with a Timer or Timer Start node: 1. In the **Workflow Builder**, drag and drop a a [Timer Start](/v1/docs/timer-start-node) or [Timer node](/v1/docs/timer-node) onto the canvas. 2. Click the **Edit** button to open the node configuration window. 3. Set the **Type** to **![Inline image displaying a selected radio button.](https://cdn.us.document360.io/15548f06-2fba-434c-b0c1-5df88317dbd7/Images/Documentation/radioComponent_teal_icon(17).png?sv=2026-02-06&spr=https&st=2026-10-26T09%3A08%3A21Z&se=2026-10-26T10%3A08%3A21Z&sr=c&sp=r&sig=YQIjSOZCkuPgyXqKkiVFO85L%2FIclQCqO%2B1rN4hMAa1M%3D) Cron**. [![A static image dispalying the Timer Start's Edit Timer Start Event settings window. The CRON timer option is highlighted and selected.](https://cdn.us.document360.io/15548f06-2fba-434c-b0c1-5df88317dbd7/Images/Documentation/timerNode_1_thumb_0_0.jpg?sv=2026-02-06&spr=https&st=2026-10-26T09%3A08%3A21Z&se=2026-10-26T10%3A08%3A21Z&sr=c&sp=r&sig=YQIjSOZCkuPgyXqKkiVFO85L%2FIclQCqO%2B1rN4hMAa1M%3D)](https://cdn.us.document360.io/15548f06-2fba-434c-b0c1-5df88317dbd7/Images/Documentation/timerNode%201.jpg?sv=2026-02-06&spr=https&st=2026-10-26T09%3A08%3A21Z&se=2026-10-26T10%3A08%3A21Z&sr=c&sp=r&sig=YQIjSOZCkuPgyXqKkiVFO85L%2FIclQCqO%2B1rN4hMAa1M%3D) 4. In the **Cron Expression** field, enter a Cron Expression. For example: to make a schedule that fires every two hours, use the expression: `0 0 0/2 * * ?`. [![A static image displaying the Timer Start's Edit Timer Start Event settings panel, the Cros Expression field is highlighted and an example value is shown.](https://cdn.us.document360.io/15548f06-2fba-434c-b0c1-5df88317dbd7/Images/Documentation/timerNode2_thumb_0_0.jpg?sv=2026-02-06&spr=https&st=2026-10-26T09%3A08%3A21Z&se=2026-10-26T10%3A08%3A21Z&sr=c&sp=r&sig=YQIjSOZCkuPgyXqKkiVFO85L%2FIclQCqO%2B1rN4hMAa1M%3D)](https://cdn.us.document360.io/15548f06-2fba-434c-b0c1-5df88317dbd7/Images/Documentation/timerNode2.jpg?sv=2026-02-06&spr=https&st=2026-10-26T09%3A08%3A21Z&se=2026-10-26T10%3A08%3A21Z&sr=c&sp=r&sig=YQIjSOZCkuPgyXqKkiVFO85L%2FIclQCqO%2B1rN4hMAa1M%3D) > [!NOTE] > A valid Cron Expression displays a green check mark and describes the schedule below the Cron expression field. 5. Click the **Save** button to save your work. ## Examples of Cron Expressions in Unqork The table below offers a list of common expressions to use for an application: | Expression | Description | | --- | --- | | `0 0 12 * * ?` | Fire at 12:00 pm every day. | | `0 15 12 * * ?` | Fire at 12:15 pm every day. | | `0 * 18 * * ?` | Fire every minute starting at 6:00 pm and ending at 6:59 pm, every day. | | `0 0/5 14 * * ?` | Fire every 5 minutes starting at 2:00 pm and ending at 2:55 pm, every day. | | `0 0/5 16,18 * * ?` | Fire every 5 minutes starting at 4:00 pm and ending at 4:55 pm, and fire every 5 minutes starting at 6:00 pm and ending at 6:55 pm, every day. | | `0 0-5 12 * * ?` | Fire every minute starting at 12:00 pm and ending at 12:05 pm, every day. | | `0 25 10 15 * ?` | Fire at 10:25 am on the 15th day of every month. | | `0 25 10 L * ?` | Fire at 10:25 am on the last day of every month. | | `0 0 9 ? * 6#3` | Fire at 9:00 am on the third Saturday of every month. | | `0 0 12 * 2 ?` | Fire at 12:00 am every day of February. | | `0 0 12 1/5 * ?` | Fire at 12 pm every 5 days every month, starting on the first day of the month. | Coordinated Universal Time (UTC) is a standard, globally-accepted timezone used to regulate clocks and time around the world.