diff --git a/reference/datetime/datetime/setisodate.xml b/reference/datetime/datetime/setisodate.xml
index ae9f287f3c..dce2124d41 100644
--- a/reference/datetime/datetime/setisodate.xml
+++ b/reference/datetime/datetime/setisodate.xml
@@ -14,7 +14,7 @@
    <modifier>public</modifier> <type>DateTime</type><methodname>DateTime::setISODate</methodname>
    <methodparam><type>int</type><parameter>year</parameter></methodparam>
    <methodparam><type>int</type><parameter>week</parameter></methodparam>
-   <methodparam choice="opt"><type>int</type><parameter>day</parameter></methodparam>
+   <methodparam choice="opt"><type>int</type><parameter>day</parameter><initializer>1</initializer></methodparam>
   </methodsynopsis>
   <para>&style.procedural;</para>
   <methodsynopsis>
@@ -22,7 +22,7 @@
    <methodparam><type>DateTime</type><parameter>object</parameter></methodparam>
    <methodparam><type>int</type><parameter>year</parameter></methodparam>
    <methodparam><type>int</type><parameter>week</parameter></methodparam>
-   <methodparam choice="opt"><type>int</type><parameter>day</parameter></methodparam>
+   <methodparam choice="opt"><type>int</type><parameter>day</parameter><initializer>1</initializer></methodparam>
   </methodsynopsis>
   <para>
    Set a date according to the ISO 8601 standard - using weeks and day offsets
diff --git a/reference/datetime/datetime/settime.xml b/reference/datetime/datetime/settime.xml
index 349da12b46..ce040a9b64 100644
--- a/reference/datetime/datetime/settime.xml
+++ b/reference/datetime/datetime/settime.xml
@@ -14,7 +14,7 @@
    <modifier>public</modifier> <type>DateTime</type><methodname>DateTime::setTime</methodname>
    <methodparam><type>int</type><parameter>hour</parameter></methodparam>
    <methodparam><type>int</type><parameter>minute</parameter></methodparam>
-   <methodparam choice="opt"><type>int</type><parameter>second</parameter></methodparam>
+   <methodparam choice="opt"><type>int</type><parameter>second</parameter><initializer>0</initializer></methodparam>
   </methodsynopsis>
   <para>&style.procedural;</para>
   <methodsynopsis>
@@ -22,7 +22,7 @@
    <methodparam><type>DateTime</type><parameter>object</parameter></methodparam>
    <methodparam><type>int</type><parameter>hour</parameter></methodparam>
    <methodparam><type>int</type><parameter>minute</parameter></methodparam>
-   <methodparam choice="opt"><type>int</type><parameter>second</parameter></methodparam>
+   <methodparam choice="opt"><type>int</type><parameter>second</parameter><initializer>0</initializer></methodparam>
   </methodsynopsis>
   <para>
    Resets the current time of the DateTime object to a different time.