[src/trunk]: src/lib/libc/time - Mention leap seconds as the reason for (00-61)

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3d6293bf8694
branches:  trunk
changeset: 535416:3d6293bf8694
user:      yamt <yamt%NetBSD.org@localhost>
date:      Sun Aug 18 06:27:49 2002 +0000

description:
- Mention leap seconds as the reason for (00-61)
- include blurb about ISO 8601 dates straight from strftime.c
from OpenBSD.

diffstat:

 lib/libc/time/strftime.3 |  20 ++++++++++++++++++--
 1 files changed, 18 insertions(+), 2 deletions(-)

diffs (44 lines):

diff -r 5353862fb0ca -r 3d6293bf8694 lib/libc/time/strftime.3
--- a/lib/libc/time/strftime.3  Sun Aug 18 05:55:24 2002 +0000
+++ b/lib/libc/time/strftime.3  Sun Aug 18 06:27:49 2002 +0000
@@ -34,9 +34,9 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     from: @(#)strftime.3   5.12 (Berkeley) 6/29/91
-.\"    $NetBSD: strftime.3,v 1.13 2002/02/07 07:00:34 ross Exp $
+.\"    $NetBSD: strftime.3,v 1.14 2002/08/18 06:27:49 yamt Exp $
 .\"
-.Dd June 29, 1991
+.Dd August 18, 2002
 .Dt STRFTIME 3
 .Os
 .Sh NAME
@@ -147,6 +147,9 @@
 using AM/PM notation.
 .It Cm \&%S
 is replaced by the second as a decimal number [00,61].
+The range of
+seconds is (00-61) instead of (00-59) to allow for the periodic occurance
+of leap seconds and double leap seconds.
 .It Cm %s
 is replaced by the number of seconds since the Epoch, UCT (see
 .Xr mktime 3 ) .
@@ -223,5 +226,18 @@
 and
 .Ql \&%V
 conversion specifications are extensions.
+.Pp
+Use of the ISO 8601 conversions may produce non-intuitive results.
+Week 01 of a year is per definition the first week which has the Thursday
+in this year, which is equivalent to the week which contains the fourth
+day of January.
+In other words, the first week of a new year is the week which has the
+majority of its days in the new year.
+Week 01 might also contain days from the previous year and the week
+before week 01 of a year is the last week (52 or 53) of the previous
+year even if it contains days from the new year.
+A week starts with Monday (day 1) and ends with Sunday (day 7).
+For example, the first week of the year 1997 lasts from
+1996-12-30 to 1997-01-05.
 .Sh BUGS
 There is no conversion specification for the phase of the moon.