49 lines
1.4 KiB
Markdown
49 lines
1.4 KiB
Markdown
# Cron
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A CRON expression is simply a string consisting of six fields that each define a specific unit of time.
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They are written in the following format:
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```
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{second} {minute} {hour} {day} {month} {day of the week}
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```
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---
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## Values
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The following values are allowed within each date/time unit placeholder.
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| Field | Allowed Values | Description |
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|---|---|---|
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| {second} | 0-59 | Trigger every {second} second(s) |
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| {minute} | 0-59 | Trigger every {minute} minute(s) |
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| {hour} | 0-23 | Trigger every {hour} hour(s) |
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| {day} | 1-31 | Trigger every {day} day(s) of month |
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| {month} | 1-12 | Trigger every {month} month(s) |
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| {day of week} | 0-6 | MON-SUN Trigger on specific {day of week} |
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---
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## Special Characters
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Additionally you can also use the following special characters to build more advanced expressions:
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| Special Character | Description |
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|---|---|
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| `*` | Trigger on tick of every time unit |
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| `,` | List separator |
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|`–` | Specifies a range |
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| `/` | Defines an increment |
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---
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## Examples
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`0 * * * * *` - Executes every minute
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`0 0 * * * *` - Executes every hour
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`0 0 0 * * *` - Executes every day
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`0 0 0 0 * *` - Executes every month
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`0 0 0 1 1 *` - Executes on first day of Jan each year
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`30 20 * * SAT` - Executes at 08:30pm every Saturday
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`30 20 * * 6` - Executes at 08:30pm every Saturday
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`0 */5 * * * *` - Executes every five minutes
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`0 0 8-10/1 * * *` - Executes every hour between 8am and 10am
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