Cron Expressions

Schedules and Auto Server Restarting in Pode use cron expressions to define when they trigger. This page is a brief overview of the expressions supported by Pode.

Basic

Pode supports all basic features of cron expressions in the following format:

<min> <hour> <day-of-month> <month> <day-of-week>

For example, if you wanted to run a schedule that triggers every midnight on a Tuesday, the following would work:

0 0 * * TUE

Whereas if you wanted a schedule to trigger on the 15th of each month, at 1am:

0 1 15 * *

Predefined

The following table outlines some of the predefined cron expressions supported by Pode; you can use these in place of normal cron expressions:

Predefined	Expression
@minutely	* * * * *
@hourly	0 * * * *
@daily	0 0 * * *
@weekly	0 0 * * 0
@monthly	0 0 1 * *
@quarterly	0 0 1 1,4,7,10 *
@yearly	0 0 1 1 *
@annually	0 0 1 1 *
@twice-hourly	0,30 * * * *
@twice-daily	0 0,12 * * *
@twice-weekly	0 0 * * 0,4
@twice-monthly	0 0 1,15 * *
@twice-yearly	0 0 1 1,6 *
@twice-annually	0 0 1 1,6 *

Advanced

Pode does have some support for advanced cron features, including its own placeholder: R.

• R: using this on an atom will use a random value between that atom's constraints, and when the expression is triggered the atom is re-randomised - you can force an initial trigger value using /R. For example: 30/R * * * * will trigger on 30mins, then a random minute afterwards; whereas using R * * * * will always trigger on a random minute between 0-59.

Helper

Pode has an inbuilt helper function, New-PodeCron, which can be used to generate cron expressions more easily. These cron expressions can then be used in Schedules and other Pode functions that use cron expressions.

The main way to use New-PodeCron is to start with the -Every parameter, such as -Every Hour or -Every Day. From this, you can customise the expression to run at specific times/days, or apply a recurring -Interval:

# Everyday, at 00:00
New-PodeCron -Every Day

# Every Tuesday and Friday, at 01:00
New-PodeCron -Every Day -Day Tuesday, Friday -Hour 1

# Every 15th of the month at 00:00
New-PodeCron -Every Month -Date 15

# Every other day, starting from the 2nd of each month, at 00:00
New-PodeCron -Every Date -Interval 2 -Date 2

# Every 1st June, at 00:00
New-PodeCron -Every Year -Month June

# Every hour, starting at 01:00
New-PodeCron -Every Hour -Hour 1 -Interval 1

# Every 15 minutes, between 01:00 and 05:00
New-PodeCron -Every Minute -Hour 1, 2, 3, 4, 5 -Interval 15

# Every hour of every Monday (ie: 00:00, 01:00, 02:00, etc.)
New-PodeCron -Every Hour -Day Monday

# Every 1st January, April, July, and October, at 00:00
New-PodeCron -Every Quarter

# Everyday at 05:15
New-PodeCron -Every Day -Hour 5 -Minute 15

You can also use New-PodeCron without using the -Every parameter. In this state, every part of the cron expression will be wildcarded by default - such as every minute, every hour, every day, etc. - unless you specify the parameter explicitly:

# Every 10 minutes on Tuesdays
New-PodeCron -Day Tuesday -Minute 0, 10, 20, 30, 40, 50

# Every minute on Tuesdays
New-PodeCron -Day Tuesday

The value returned by New-PodeCron is a valid cron expression, that can then be used when creating Schedules:

# Every Tuesday, at 00:05
$cron = New-PodeCron -Day Tuesday -Hour 0 -Minute 5

Add-PodeSchedule -Name 'date' -Cron $cron -ScriptBlock {
    Write-Host "$([DateTime]::Now)"
}