Schedule Format

Proxmox VE has a very flexible scheduling configuration. It is based on the systemd time calendar event format.
[see man 7 systemd.time for more information]
Calendar events may be used to refer to one or more points in time in a single expression.

Such a calendar event uses the following format:

[WEEKDAY] [[YEARS-]MONTHS-DAYS] [HOURS:MINUTES[:SECONDS]]

This format allows you to configure a set of days on which the job should run. You can also set one or more start times. It tells the replication scheduler the moments in time when a job should start. With this information we, can create a job which runs every workday at 10 PM: 'mon,tue,wed,thu,fri 22' which could be abbreviated to: 'mon..fri 22', most reasonable schedules can be written quite intuitive this way.

Hours are formatted in 24-hour format.

To allow a convenient and shorter configuration, one or more repeat times per guest can be set. They indicate that replications are done on the start-time(s) itself and the start-time(s) plus all multiples of the repetition value. If you want to start replication at 8 AM and repeat it every 15 minutes until 9 AM you would use: '8:00/15'

Here you see that if no hour separation (:), is used the value gets interpreted as minute. If such a separation is used, the value on the left denotes the hour(s), and the value on the right denotes the minute(s). Further, you can use * to match all possible values.

To get additional ideas look at more Examples below.

Detailed Specification

weekdays: Days are specified with an abbreviated English version: sun, mon, tue, wed, thu, fri and sat. You may use multiple days as a comma-separated list. A range of days can also be set by specifying the start and end day separated by “..”, for example mon..fri. These formats can be mixed. If omitted '*' is assumed.
time-format: A time format consists of hours and minutes interval lists. Hours and minutes are separated by ':'. Both hour and minute can be list and ranges of values, using the same format as days. First are hours, then minutes. Hours can be omitted if not needed. In this case '*' is assumed for the value of hours. The valid range for values is 0-23 for hours and 0-59 for minutes.

You can use systemd-analyze calendar to see whether a given calendar event specification is valid and when it would be triggered next. By passing the --iterations=<N> flag you can also let it output the next <N> times the calendar event would trigger (you need to replace <N> with a valid integer).

Examples:

There are some special values that have a specific meaning:

Table 1. Special Values
Value	Syntax
`minutely`	`--* ::00`
`hourly`	`--* *:00:00`
`daily`	`--* 00:00:00`
`weekly`	`mon --* 00:00:00`
`monthly`	`--01 00:00:00`
`yearly` or `annually`	`*-01-01 00:00:00`
`quarterly`	`*-01,04,07,10-01 00:00:00`
`semiannually` or `semi-annually`	`*-01,07-01 00:00:00`

Table 2. Schedule Examples
Schedule String	Alternative	Meaning
mon,tue,wed,thu,fri	mon..fri	Every working day at 0:00
sat,sun	sat..sun	Only on weekends at 0:00
mon,wed,fri	—	Only on Monday, Wednesday and Friday at 0:00
12:05	12:05	Every day at 12:05 PM
*/5	0/5	Every five minutes
mon..wed 30/10	mon,tue,wed 30/10	Monday, Tuesday, Wednesday 30, 40 and 50 minutes after every full hour
mon..fri 8..17,22:0/15	—	Every working day every 15 minutes between 8 AM and 6 PM and between 10 PM and 11 PM
fri 12..13:5/20	fri 12,13:5/20	Friday at 12:05, 12:25, 12:45, 13:05, 13:25 and 13:45
12,14,16,18,20,22:5	12/2:5	Every day starting at 12:05 until 22:05, every 2 hours
*	*/1	Every minute (minimum interval)
*-05	—	On the 5th day of every Month
Sat *-1..7 15:00	—	First Saturday each Month at 15:00
2015-10-21	—	21st October 2015 at 00:00