analyze: add new "calendar" command

This little new command can parse, validate, normalize calendar events,
and calculate when they will elapse next. This should be useful for
anyone writing calendar events and who'd like to validate the expression
before running them as timer units.

1 files changed, 12 insertions, 0 deletions

diff --git a/man/systemd-analyze.xml b/man/systemd-analyze.xml
index 956790c50c..876f96d559 100644
--- a/man/systemd-analyze.xml
+++ b/man/systemd-analyze.xml
@@ -125,6 +125,12 @@
       <arg choice="plain">verify</arg>
       <arg choice="opt" rep="repeat"><replaceable>FILES</replaceable></arg>
     </cmdsynopsis>
+    <cmdsynopsis>
+      <command>systemd-analyze</command>
+      <arg choice="opt" rep="repeat">OPTIONS</arg>
+      <arg choice="plain">calendar</arg>
+      <arg choice="plain" rep="repeat"><replaceable>SPECS</replaceable></arg>
+    </cmdsynopsis>
   </refsynopsisdiv>
 
   <refsect1>
@@ -220,6 +226,12 @@
     All units files present in the directories containing the command line arguments will
     be used in preference to the other paths.</para>
 
+    <para><command>systemd-analyze calendar</command> will parse and normalize repetitive calendar time events, and
+    will calculate when they will elapse next. This takes the same input as the <varname>OnCalendar=</varname> setting
+    in <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>, following the
+    syntax described in
+    <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
+
     <para>If no command is passed, <command>systemd-analyze
     time</command> is implied.</para>