-<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.505 2010/02/19 00:15:25 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.506 2010/02/23 16:14:25 momjian Exp $ -->
<chapter id="functions">
<title>Functions and Operators</title>
<listitem>
<para>
<function>to_char(interval)</function> formats <literal>HH</> and
- <literal>HH12</> as hours in a single day, while <literal>HH24</>
- can output hours exceeding a single day, e.g., >24.
+ <literal>HH12</> as shown on a 12-hour clock, i.e. zero hours
+ and 36 hours output as <literal>12</>, while <literal>HH24</>
+ outputs the full hour value, which can exceed 23 for intervals.
</para>
</listitem>
/* -----------------------------------------------------------------------
* formatting.c
*
- * $PostgreSQL: pgsql/src/backend/utils/adt/formatting.c,v 1.165 2010/02/23 06:29:01 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/formatting.c,v 1.166 2010/02/23 16:14:26 momjian Exp $
*
*
* Portions Copyright (c) 1999-2010, PostgreSQL Global Development Group
break;
case DCH_HH:
case DCH_HH12:
+ /* display time as shown on a 12-hour clock, even for intervals */
sprintf(s, "%0*d", S_FM(n->suffix) ? 0 : 2,
- is_interval ? tm->tm_hour :
- tm->tm_hour % (HOURS_PER_DAY / 2) == 0 ?
- 12 : tm->tm_hour % (HOURS_PER_DAY / 2));
+ tm->tm_hour % (HOURS_PER_DAY / 2) == 0 ? 12 :
+ tm->tm_hour % (HOURS_PER_DAY / 2));
if (S_THth(n->suffix))
str_numth(s, s, S_TH_TYPE(n->suffix));
s += strlen(s);