* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/utils/timestamp.h,v 1.52 2005/07/21 20:37:21 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/utils/timestamp.h,v 1.53 2005/07/22 05:08:26 momjian Exp $
*
*-------------------------------------------------------------------------
*/
* DAYS_PER_MONTH is very imprecise. The more accurate value is
* 365.2425/12 = 30.436875, or '30 days 10:29:06'. Right now we only
* return an integral number of days, but someday perhaps we should
- * also return a 'time' value to be used as well.
+ * also return a 'time' value to be used as well. ISO 8601 suggests
+ * 30 days.
*/
#define DAYS_PER_MONTH 30 /* assumes exactly 30 days per month */
#define HOURS_PER_DAY 24 /* assume no daylight savings time changes */
/*
* This doesn't adjust for uneven daylight savings time intervals or leap
- * seconds, and it crudely estimates leap years.
+ * seconds, and it crudely estimates leap years. A more accurate value
+ * for days per years is 365.2422.
*/
#define SECS_PER_YEAR (36525 * 864) /* avoid floating-point computation */
#define SECS_PER_DAY 86400
* DAYS_PER_MONTH is very imprecise. The more accurate value is
* 365.2425/12 = 30.436875, or '30 days 10:29:06'. Right now we only
* return an integral number of days, but someday perhaps we should
- * also return a 'time' value to be used as well.
+ * also return a 'time' value to be used as well. ISO 8601 suggests
+ * 30 days.
*/
#define DAYS_PER_MONTH 30 /* assumes exactly 30 days per month */
#define HOURS_PER_DAY 24 /* assume no daylight savings time changes */
/*
* This doesn't adjust for uneven daylight savings time intervals or leap
- * seconds, and it crudely estimates leap years.
+ * seconds, and it crudely estimates leap years. A more accurate value
+ * for days per years is 365.2422.
*/
#define SECS_PER_YEAR (36525 * 864) /* avoid floating-point computation */
#define SECS_PER_DAY 86400