Custom Scheduling

Overview

Swivel uses a specific scheduling syntax for several of its jobs. On most screens, they are in a user-friendly format with a drop-down menu, but they may still be customised for specific requirements. This document covers the customised format.

Custom Scheduling

A cron expression is a string comprised of 6 or 7 fields separated by white space. The 6 mandatory and 1 optional fields are as follows:

Custom Scheduling Fields

Field Name

Seconds

Minutes

Hours

Day-of-month

Month

Day-of-week

Year (Optional)

Allowed Values

0-59

0-59

0-23

1-31

1-12 or JAN-DEC

1-7 or SUN-SAT

1970-2099

Allowed Special Characters

, - * /

, - * /

, - * /

, - * ? / L W C

, - * /

, - * ? / L C #

, - * /

Special Characters

  • * : Used to specify all values. For example, “*” in the minute field means “every minute”.

  • ? : Allowed for the day-of-month and day-of-week fields. It specifies ‘no specific value’. Use this when you need to specify something in one of the two fields, but not the other.

  • - : Used to specify ranges. For example “10-12” in the hour field means “the hours 10, 11 and 12”.

  • , : Used to specify additional values. For example “MON,WED,FRI” in the day-of-week field means “the days Monday, Wednesday, and Friday”.

  • / : Used to specify increments. For example “0/15” in the seconds field means “the seconds 0, 15, 30, and 45”. And “5/15” in the seconds field means “the seconds 5, 20, 35, and 50”. Specifying ‘*’ before the ‘/’ is equivalent to starting at 0. Note: “7/6” in the month field only turns on month “7”, it does NOT mean every 6th month.

  • LAllowed for the day-of-month and day-of-week fields. Short-hand for “last”.

    • In day-of-month: “the last day of the month” (day 31 for Jan, 28 for Feb non-leap).

    • In day-of-week: “7” or “SAT”.

    • In day-of-week after another value: “the last xxx day of the month” - e.g., “6L” means “the last Friday of the month”.

    • Warning: Do not specify lists or ranges when using ‘L’.

  • WAllowed for the day-of-month field. Specifies the weekday (Monday-Friday) nearest the given day. E.g., “15W” means “the nearest weekday to the 15th of the month”.

    • If the 15th is Saturday, it fires on Friday the 14th.

    • If the 15th is Sunday, it fires on Monday the 16th.

    • It will not ‘jump’ over month boundaries (e.g., “1W” where the 1st is Saturday will fire on Monday the 3rd).

    • Note: ‘W’ can only be used when the day-of-month is a single day.

  • LW : “Last weekday of the month”.

  • #Allowed for the day-of-week field. Specifies “the nth” XXX day of the month.

    • “6#3” = the third Friday of the month (Day 6 = Friday, #3 = 3rd occurrence).

    • “2#1” = the first Monday.

    • “4#5” = the fifth Wednesday.

  • CAllowed for the day-of-month and day-of-week fields. Short-hand for “calendar”. Values are calculated against the associated calendar. If no calendar is associated, it includes all days.

    • “5C” in day-of-month = “the first day included by the calendar on or after the 5th”.

    • “1C” in day-of-week = “the first day included by the calendar on or after Sunday”.

Note

The legal characters and the names of months and days of the week are not case sensitive.

Examples

  • 0 0 12 * * ? : Fire at 12pm (noon) every day

  • 0 15 10 ? * * : Fire at 10:15am every day

  • 0 15 10 * * ? : Fire at 10:15am every day

  • 0 15 10 * * ? * : Fire at 10:15am every day

  • 0 15 10 * * ? 2005 : Fire at 10:15am every day during the year 2005

  • 0 * 14 * * ? : Fire every minute starting at 2pm and ending at 2:59pm, every day

  • 0 0/5 14 * * ? : Fire every 5 minutes starting at 2pm and ending at 2:55pm, every day

  • 0 0/5 14,18 * * ? : Fire every 5 minutes starting at 2pm and ending at 2:55pm, AND fire every 5 minutes starting at 6pm and ending at 6:55pm, every day

  • 0 0-5 14 * * ? : Fire every minute starting at 2pm and ending at 2:05pm, every day

  • 0 10,44 14 ? 3 WED : Fire at 2:10pm and at 2:44pm every Wednesday in the month of March.

  • 0 15 10 ? * MON-FRI : Fire at 10:15am every Monday, Tuesday, Wednesday, Thursday and Friday

  • 0 15 10 15 * ? : Fire at 10:15am on the 15th day of every month

  • 0 15 10 L * ? : Fire at 10:15am on the last day of every month

  • 0 15 10 ? * 6L : Fire at 10:15am on the last Friday of every month

  • 0 15 10 ? * 6L 2002-2005 : Fire at 10:15am on every last Friday of every month during the years 2002, 2003, 2004 and 2005

  • 0 15 10 ? * 6#3 : Fire at 10:15am on the third Friday of every month

  • 0 0 11 1-31/2 * ? : Fire on odd days at 11.00

  • 0 0 11 2-31/2 * ? : Fire on even days at 11.00

Warning

Pay attention to the effects of ? and * in the day-of-week and day-of-month fields!