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Cron Expressions

Actian Data Platform lets you set a schedule warehouse actions using a cron expression, which is a specially formatted text string.

The following example is a cron expression representing a schedule that will run at 1:25 p.m. on the first day of each month.

0 25 13 1 * ? *

Building a Cron Expression

A cron expression is composed of six or seven values separated by spaces. Each of these values represents part of the schedule and can be either a number or a certain special character.

Expression Fields

Field Required Values Special Characters
Second Yes 0–59 , - * /
Minute Yes 0–59 , - * /
Hour Yes 0–23 , - * /
Day of Month Yes 1–31 , - * / L W ?
Month Yes 1–12 or JAN–DEC , - * /
Day of Week Yes 1–7 or SUN–SAT , - * / # ?
Year No 1970–2099 , - * /

Special Characters

Special characters let you specify wildcards, ranges, and other conditions for each field.

Character Description Examples
* All values for the field are selected. * in the Hour field means every hour.
? No specific value required. Only usable in the Day of Month and Day of Week fields. To set a schedule that runs on Sundays regardless of the day of the month, use a ? in the Day of Month field and a 1 in the Day of Week field.
- Specify a range (inclusive) between 2 values. 1–3 in the Hour field (along with a 0 in the Minute and Second fields) is triggered at 1:00 a.m., 2:00 a.m., and 3:00 a.m.
, Separate multiple values. 1,3 in the Hour field means 1:00 a.m. and 3:00 a.m.
/ Incremental trigger. Enter in the format X/Y, where X is the starting value and Y is the increment. 0/15 in the Minute field means the schedule begins at minute 00 and then runs every 15 minutes thereafter.
L Last day of the month or week.Can be combined with other values in each field as illustrated below.
• Day of Month: L–X, where X is a number of days to offset from the last calendar day of the month.
• Day of Week: XL, where X is a day value (1–7).		 L in the Day of Month field means the last calendar day of the month.L–2 in the Day of Month field means the second-to-last calendar day of the month.L in the Day of Week field simply means 7 (Saturday).7L in the Day of Week field means the last Saturday of the month.
W Weekday (Monday–Friday) nearest the given day. Enter in the format XW, where X is the day of the month. 12W in the Day of Month field is triggered on the 12th day of the month if that day falls on a weekday. If the 12th falls on a Saturday or Sunday, the schedule runs on the following Monday.LW in the Day of Month field is triggered on the last weekday of the month.
# Exact monthly instance of the specified day of the week. Enter in the format X#Y, where X is the day of the week and Y is the instance.Note:A value using X#5 will not be triggered for the month if there are not 5 of day X within the month. 2#3 in the Day of Week field means the 3rd Monday each month.

Examples

Following are several examples of simple and complex cron expressions.

Simple Daily

Run the schedule at 9:00 a.m. every day.

0 0 9 * * ? *
Seconds Minutes Hours Day of Month Month Day of Week Year
0 0 9 * * ? *

Complex Daily

Run the schedule every 5 seconds for 1 minute beginning at 9:00 a.m. every day.

0/5 0 9 * * ? *
Seconds Minutes Hours Day of Month Month Day of Week Year
0/5 0 9 * * ? *

Simple Weekly

Run the schedule at 9:25 a.m. every Friday.

0 25 9 * * 6 *
Seconds Minutes Hours Day of Month Month Day of Week Year
0 25 9 * * 6 *

Complex Weekly

Run the schedule at 9:00 a.m. every Friday, but only in January or February of 2019.

0 0 9 * 1,2 6 2019
Seconds Minutes Hours Day of Month Month Day of Week Year
0 0 9 * 1,2 6 2019

Monthly

Run the schedule at 9:00 a.m., 9:22 a.m., and 9:44 a.m. on the last Thursday of each month.

0 0,22,44 9 ? * L5 *
Seconds Minutes Hours Day of Month Month Day of Week Year
0 0,22,44 9 ? * L5 *

Yearly

Run the schedule at 2:27 p.m., 3:27 p.m., and 4:27 p.m. on the weekday nearest the 12th day of the month every October.

0 27 14-16 12W 10 ? *
Seconds Minutes Hours Day of Month Month Day of Week Year
0 27 14-16 12W 10 ? *