diff --git a/reference/mongo/mongodate/construct.xml b/reference/mongo/mongodate/construct.xml
index 9041acbe25..9470a79146 100644
--- a/reference/mongo/mongodate/construct.xml
+++ b/reference/mongo/mongodate/construct.xml
@@ -29,7 +29,7 @@
      </term>
      <listitem>
       <para>
-       Number of seconds since January 1st, 1970.
+       Number of seconds since the epoch (i.e. 1 Jan 1970 00:00:00.000 UTC).
       </para>
      </listitem>
     </varlistentry>     
diff --git a/reference/mongo/mongotimestamp/construct.xml b/reference/mongo/mongotimestamp/construct.xml
index c3651d140b..b0741b5e01 100644
--- a/reference/mongo/mongotimestamp/construct.xml
+++ b/reference/mongo/mongotimestamp/construct.xml
@@ -32,7 +32,7 @@
      </term>
      <listitem>
       <para>
-       Number of seconds since January 1st, 1970.
+       Number of seconds since the epoch (i.e. 1 Jan 1970 00:00:00.000 UTC).
       </para>
      </listitem>
     </varlistentry>