proxmox-backup/docs/calendarevents.rst
Dylan Whyte 2bc1250c28 docs: language fixup: faq and appendix
minor formatting and language fixes to the faq section and the appendix

Signed-off-by: Dylan Whyte <d.whyte@proxmox.com>
2021-11-02 07:12:07 +01:00

100 lines
4.4 KiB
ReStructuredText

.. _calendar-event-scheduling:
Calendar Events
===============
Introduction and Format
-----------------------
Certain tasks, for example pruning and garbage collection, need to be
performed on a regular basis. Proxmox Backup Server uses a format inspired
by the systemd Time and Date Specification (see `systemd.time manpage`_)
called `calendar events` for its schedules.
`Calendar events` are expressions to specify one or more points in time.
They are mostly compatible with systemd's calendar events.
The general format is as follows:
.. code-block:: console
:caption: Calendar event
[WEEKDAY] [[YEARS-]MONTHS-DAYS] [HOURS:MINUTES[:SECONDS]]
Note that there either has to be at least a weekday, date or time part.
If the weekday or date part is omitted, all (week)days are included.
If the time part is omitted, the time 00:00:00 is implied.
(e.g. '2020-01-01' refers to '2020-01-01 00:00:00')
Weekdays are specified with the abbreviated English version:
`mon, tue, wed, thu, fri, sat, sun`.
Each field can contain multiple values in the following formats:
* comma-separated: e.g., 01,02,03
* as a range: e.g., 01..10
* as a repetition: e.g, 05/10 (means starting at 5 every 10)
* and a combination of the above: e.g., 01,05..10,12/02
* or a `*` for every possible value: e.g., \*:00
There are some special values that have a specific meaning:
================================= ==============================
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`
================================= ==============================
Here is a table with some useful examples:
======================== ============================= ===================================
Example Alternative Explanation
======================== ============================= ===================================
`mon,tue,wed,thu,fri` `mon..fri` Every working day at 00:00
`sat,sun` `sat..sun` Only on weekends at 00:00
`mon,wed,fri` -- Monday, Wednesday, Friday at 00:00
`12:05` -- Every day at 12:05 PM
`*:00/5` `0/1:0/5` 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
`*:*` `0/1:0/1` 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
======================== ============================= ===================================
Differences to systemd
----------------------
Not all features of systemd calendar events are implemented:
* no Unix timestamps (e.g. `@12345`): instead use date and time to specify
a specific point in time
* no timezone: all schedules use the timezone of the server
* no sub-second resolution
* no reverse day syntax (e.g. 2020-03~01)
* no repetition of ranges (e.g. 1..10/2)
Notes on Scheduling
-------------------
In `Proxmox Backup`_, scheduling for most tasks is done in the
`proxmox-backup-proxy`. This daemon checks all job schedules
every minute, to see if any are due. This means that even though
`calendar events` can contain seconds, it will only be checked
once per minute.
Also, all schedules will be checked against the timezone set
in the `Proxmox Backup`_ server.