diff --git a/functions/calendar.xml b/functions/calendar.xml
index 8a85e387f6..75fef8e353 100644
--- a/functions/calendar.xml
+++ b/functions/calendar.xml
@@ -1,29 +1,32 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.21 $ -->
+<!-- $Revision: 1.22 $ -->
  <reference id="ref.calendar">
   <title>Calendar functions</title>
   <titleabbrev>Calendar</titleabbrev>
-
   <partintro>
-   <para>
-    The calendar functions are only available if you have compiled
-    the calendar extension, found in either the "dl" or "ext"
-    subdirectories of your PHP source code.
-    Please see the README file before using it.
-   </para>
-   <para>
-    The calendar extension presents a series of functions to simplify
-    converting between different calendar formats.  The intermediary
-    or standard it is based on is the Julian Day Count.  The Julian
-    Day Count is a count of days starting way earlier than any date
-    most people would need to track (somewhere around 4000bc).  To
-    convert between calendar systems, you must first convert to Julian
-    Day Count, then to the calendar system of your choice.  Julian Day
-    Count is very different from the Julian Calendar!  For more
-    information on calendar systems visit <ulink
-    url="&url.calendar;">&url.calendar;</ulink>.  Excerpts from this
-    page are included in these instructions, and are in quotes.
-   </para>
+   <section>
+    <title>Introduction</title>
+    <para>
+     The calendar extension presents a series of functions to simplify
+     converting between different calendar formats.  The intermediary
+     or standard it is based on is the Julian Day Count.  The Julian
+     Day Count is a count of days starting way earlier than any date
+     most people would need to track (somewhere around 4000bc).  To
+     convert between calendar systems, you must first convert to Julian
+     Day Count, then to the calendar system of your choice.  Julian Day
+     Count is very different from the Julian Calendar!  For more
+     information on calendar systems visit <ulink
+     url="&url.calendar;">&url.calendar;</ulink>.  Excerpts from this
+     page are included in these instructions, and are in quotes.
+    </para>
+   </section>
+   <section>
+    <title>Installation</title>
+    <para>
+     To get these functions to work, you have to compile PHP with
+     <option role="configure">--enable-calendar</option>.
+    </para>
+   </section>
   </partintro>
 
   <refentry id="function.jdtogregorian">