rsnapshot systemd timers

rsnapshot-systemd

# systemd list-timers
----------------------
NEXT                         LEFT                LAST                         PASSED       UNIT                         ACTIVATES
Sat 2016-05-14 21:00:00 EDT  2min 56s ago        Sat 2016-05-14 21:00:00 EDT  2min 56s ago rsnapshot-hourly.timer       rsnapshot@hourly.service
Sat 2016-05-14 23:50:00 EDT  2h 47min left       Fri 2016-05-13 23:50:00 EDT  21h ago      rsnapshot-daily.timer        rsnapshot@daily.service
...
Sun 2016-05-15 23:40:00 EDT  1 day 2h left       n/a                          n/a          rsnapshot-weekly.timer       rsnapshot@weekly.service
Sun 2016-06-05 23:30:00 EDT  3 weeks 1 days left n/a                          n/a          rsnapshot-monthly.timer      rsnapshot@monthly.service


rsnapshot@.service
------------------
[Unit]
Description=rsnapshot (%I) backup

[Service]
Type=oneshot
Nice=19
IOSchedulingClass=3
ExecStart=/usr/bin/rsnapshot %I


rsnapshot-hourly.timer
----------------------
[Unit]
Description=rsnapshot hourly backup

[Timer]
OnCalendar=hourly
Persistent=true
Unit=rsnapshot@hourly.service

[Install]
WantedBy=timers.target


rsnapshot-daily.timer
---------------------
[Unit]
Description=rsnapshot daily backup

[Timer]
OnCalendar=23:50
Persistent=true
Unit=rsnapshot@daily.service

[Install]
WantedBy=timers.target


rsnapshot-weekly.timer
----------------------
[Unit]
Description=rsnapshot weekly backup

[Timer]
OnCalendar=Sun, 23:40
Persistent=true
Unit=rsnapshot@weekly.service

[Install]
WantedBy=timers.target


rsnapshot-monthly.timer
-----------------------
[Unit]
Description=rsnapshot monthly backup

[Timer]
OnCalendar=Sun *-*-1,2,3,4,5,6,7 23:30
Persistent=true
Unit=rsnapshot@monthly.service

[Install]
WantedBy=timers.target

For anyone who comes across this as I did, I wanted to note something helpful for those duplicating your example.

Firstly, ranges were added at some point the last couple of years for date strings. So the monthly OnCalendar string can be reduced to the following: Sun *-*-1..7 23:30.

Personally, I fought with the OnCalendar spec to make things behave exactly as I wanted. There is a tool to ease testing of OnCalendar strings, systemd-analyze. For example, in testing a quarterly timer I can run the following:

$ systemd-analyze calendar "Sun *-1,4,7,10-1..7 23:01:00"
  Original form: Sun *-1,4,7,10-1..7 23:01:00
Normalized form: Sun *-01,04,07,10-01..07 23:01:00
    Next elapse: Sun 2018-07-01 23:01:00 PDT
       (in UTC): Mon 2018-07-02 06:01:00 UTC
       From now: 1 months 16 days left
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