Update docs to reflect the fact that we can now deal with DST rules

outside the 32-bit-time_t range.  Also, refer to Olson's tz database
as the 'zoneinfo' database, a name that upstream sometimes uses, not
'zic database' which they never use.

doc/src/sgml/datatype.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.224 2008/02/13 22:46:55 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.225 2008/02/16 21:51:04 tgl Exp $ -->
 
  <chapter id="datatype">
   <title id="datatype-title">Data Types</title>
@@ -2187,11 +2187,11 @@ January 8 04:05:06 1999 PST
     world became somewhat standardized during the 1900's,
     but continue to be prone to arbitrary changes, particularly with
     respect to daylight-savings rules.
-    <productname>PostgreSQL</productname> currently supports daylight-savings
-    rules over the time period 1902 through 2038 (corresponding to the full
-    range of conventional Unix system time).  Times outside that range are
-    taken to be in <quote>standard time</> for the selected time zone, no
-    matter what part of the year they fall in.
+    <productname>PostgreSQL</productname> uses the widely-used
+    <literal>zoneinfo</> time zone database for information about
+    historical time zone rules.  For times in the future, the assumption
+    is that the latest known rules for a given time zone will
+    continue to be observed indefinitely far into the future.
    </para>
 
     <para>
@@ -2254,7 +2254,7 @@ January 8 04:05:06 1999 PST
         <literal>pg_timezone_names</literal> view (see <xref
         linkend="view-pg-timezone-names">).
         <productname>PostgreSQL</productname> uses the widely-used
-        <literal>zic</> time zone data for this purpose, so the same
+        <literal>zoneinfo</> time zone data for this purpose, so the same
         names are also recognized by much other software.
        </para>
       </listitem>
@@ -2287,7 +2287,7 @@ January 8 04:05:06 1999 PST
         be functionally equivalent to USA East Coast time.  When a
         daylight-savings zone name is present, it is assumed to be used
         according to the same daylight-savings transition rules used in the
-        <literal>zic</> time zone database's <filename>posixrules</> entry.
+        <literal>zoneinfo</> time zone database's <filename>posixrules</> entry.
         In a standard <productname>PostgreSQL</productname> installation,
         <filename>posixrules</> is the same as <literal>US/Eastern</>, so
         that POSIX-style time zone specifications follow USA daylight-savings

doc/src/sgml/datetime.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/datetime.sgml,v 2.58 2007/12/15 01:18:33 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/datetime.sgml,v 2.59 2008/02/16 21:51:04 tgl Exp $ -->
 
  <appendix id="datetime-appendix">
   <title>Date/Time Support</title>
@@ -430,7 +430,7 @@
     For reference purposes, a standard installation also contains files
     <filename>Africa.txt</>, <filename>America.txt</>, etc, containing
     information about every time zone abbreviation known to be in use
-    according to the <literal>zic</> timezone database.  The zone name
+    according to the <literal>zoneinfo</> timezone database.  The zone name
     definitions found in these files can be copied and pasted into a custom
     configuration file as needed.  Note that these files cannot be directly
     referenced as <literal>timezone_abbreviations</> settings, because of

doc/src/sgml/installation.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/installation.sgml,v 1.300 2008/01/31 20:29:30 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/installation.sgml,v 1.301 2008/02/16 21:51:04 tgl Exp $ -->
 
 <chapter id="installation">
  <title><![%standalone-include[<productname>PostgreSQL</>]]>
@@ -1032,7 +1032,7 @@ su - postgres
         <para>
          <productname>PostgreSQL</> includes its own time zone database,
          which it requires for date and time operations.  This time zone
-         database is in fact compatible with the <quote>zic</> time zone
+         database is in fact compatible with the <quote>zoneinfo</> time zone
          database provided by many operating systems such as FreeBSD,
          Linux, and Solaris, so it would be redundant to install it again.
          When this option is used, the system-supplied time zone database