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>

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.