diff --git a/admin-guide/puppet/profiles/custom_timers.rst b/admin-guide/puppet/profiles/custom_timers.rst
index 90e280cf..4feca675 100644
--- a/admin-guide/puppet/profiles/custom_timers.rst
+++ b/admin-guide/puppet/profiles/custom_timers.rst
@@ -20,6 +20,7 @@ Parameters
 description                      String
 command                          String
 on_calendar                      String
+persistent                       Boolean   false
 ===============================  ========  ================================================
 
 
@@ -38,3 +39,7 @@ and a check is performed against this.
 ~~~~~~~~~~~~~~~
 The definition of the timer execution time. See `OnCalendar` on systemd.timer(5).
 
+``persistent``
+~~~~~~~~~~~~~
+If set will run the timer immediately at bootup if the device was switched off at the time
+of the last scheduled run.
diff --git a/rhel8/software.md b/rhel8/software.md
index 396f15b3..a174a092 100644
--- a/rhel8/software.md
+++ b/rhel8/software.md
@@ -137,7 +137,7 @@ For each time following keys are mandatory
 
 - `description` for a short explaination what it is about
 - `command` for the command to run
-- `on_calendar`defining when it should run using the [`systemd` calendar event format](https://www.freedesktop.org/software/systemd/man/systemd.time.html#Calendar%20Events)
+- `on_calendar` defining when it should run using the [`systemd` calendar event format](https://www.freedesktop.org/software/systemd/man/systemd.time.html#Calendar%20Events), (alternatively see also chapter "CALENDAR EVENTS" `man systemd.date`)
 
 Optional is
 - `persistence` which signals if the timer should run immediately after boot when the node was switched of on the last suggested run time (default is `false`)