index 67d802b02c24c15734b722d19ac460abdf433b4e..d20116340752705e0276dbc3e00958d68e181a8f 100644 (file)
@@ -9941,6 +9941,20 @@ SELECT date_trunc('hour', INTERVAL '3 days 02:47:33');
aligned with a specified origin.
</para>
+ <para>
+<synopsis>
+date_trunc(<replaceable>stride</replaceable>, <replaceable>source</replaceable>, <replaceable>origin</replaceable>)
+</synopsis>
+ <replaceable>source</replaceable> is a value expression of type
+ <type>timestamp</type> or <type>timestamp with time zone</type>. (Values
+ of type <type>date</type> are cast automatically to
+ <type>timestamp</type>.) <replaceable>stride</replaceable> is a value
+ expression of type <type> interval</type>. The return value is likewise
+ of type <type>timestamp</type> or <type>timestamp with time zone</type>,
+ and it marks the beginning of the bin into which the
+ <replaceable>source</replaceable> is placed.
+ </para>
+
<para>
Examples:
<screen>
@@ -9958,6 +9972,10 @@ SELECT date_bin('15 minutes', TIMESTAMP '2020年02月11日 15:44:17', TIMESTAMP '2001-0
that <function>date_bin</function> can truncate to an arbitrary interval.
</para>
+ <para>
+ Negative intervals are allowed and are treated the same as positive intervals.
+ </para>
+
<para>
The <parameter>stride</parameter> interval cannot contain units of month
or larger.