linkend="datatype-datetime"/>.

</para>

<para>

In addition, the usual comparison operators shown in

<xref linkend="functions-comparison-op-table"/> are available for the

date/time types. Dates and timestamps (with or without time zone) are

all comparable, while times (with or without time zone) and intervals

can only be compared to other values of the same data type. When

comparing a timestamp without time zone to a timestamp with time zone,

the former value is assumed to be given in the time zone specified by

the <xref linkend="guc-timezone"/> configuration parameter, and is

rotated to UTC for comparison to the latter value (which is already

in UTC internally). Similarly, a date value is assumed to represent

midnight in the <varname>TimeZone</varname> zone when comparing it

to a timestamp.

</para>

<para>

All the functions and operators described below that take <type>time</type> or <type>timestamp</type>

inputs actually come in two variants: one that takes <type>time with time zone</type> or <type>timestamp

with time zone</type>, and one that takes <type>time without time zone</type> or <type>timestamp without time zone</type>.

For brevity, these variants are not shown separately. Also, the

<literal>+</literal> and <literal>*</literal> operators come in commutative pairs (for

example both date + integer and integer + date); we show only one of each

such pair.

example both <type>date</type> <literal>+</literal> <type>integer</type>

and <type>integer</type> <literal>+</literal> <type>date</type>); we show

only one of each such pair.

</para>

<table id="operators-datetime-table">