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authorChong Yidong2009-08-09 23:39:59 +0000
committerChong Yidong2009-08-09 23:39:59 +0000
commit4c39f404d52c888bd314a3ffed4c6306537343fe (patch)
tree0e9346e0722fd3a864b264a5763176af1913500d /doc/misc
parenta9cc50d99941cb175c93c732df3b1fb12a72419f (diff)
downloademacs-4c39f404d52c888bd314a3ffed4c6306537343fe.tar.gz
emacs-4c39f404d52c888bd314a3ffed4c6306537343fe.zip
* calc.texi (Date Forms): Fix typos.
Diffstat (limited to 'doc/misc')
-rw-r--r--doc/misc/ChangeLog4
-rw-r--r--doc/misc/calc.texi30
2 files changed, 19 insertions, 15 deletions
diff --git a/doc/misc/ChangeLog b/doc/misc/ChangeLog
index 0ec28f3c160..e0fbe264175 100644
--- a/doc/misc/ChangeLog
+++ b/doc/misc/ChangeLog
@@ -1,3 +1,7 @@
12009-08-09 Colin Williams <lackita@gmail.com> (tiny change)
2
3 * calc.texi (Date Forms): Fix typos.
4
12009-08-08 Glenn Morris <rgm@gnu.org> 52009-08-08 Glenn Morris <rgm@gnu.org>
2 6
3 * org.texi (Agenda commands): Restore clobbered change. 7 * org.texi (Agenda commands): Restore clobbered change.
diff --git a/doc/misc/calc.texi b/doc/misc/calc.texi
index 4653a9446a4..49a5260af6c 100644
--- a/doc/misc/calc.texi
+++ b/doc/misc/calc.texi
@@ -11093,29 +11093,29 @@ days 0 and @mathit{-1} respectively in Calc's internal numbering scheme.
11093 11093
11094@cindex Julian day counting 11094@cindex Julian day counting
11095Another day counting system in common use is, confusingly, also called 11095Another day counting system in common use is, confusingly, also called
11096``Julian.'' The Julian day number is the numbers of days since 11096``Julian.'' The Julian day number is the numbers of days since
1109712:00 noon (GMT) on Jan 1, 4713 BC, which in Calc's scheme (in GMT) 1109712:00 noon (GMT) on Jan 1, 4713 BC, which in Calc's scheme (in GMT)
11098is @mathit{-1721423.5} (recall that Calc starts at midnight instead 11098is @mathit{-1721423.5} (recall that Calc starts at midnight instead
11099of noon). Thus to convert a Calc date code obtained by unpacking a 11099of noon). Thus to convert a Calc date code obtained by unpacking a
11100date form into a Julian day number, simply add 1721423.5 after 11100date form into a Julian day number, simply add 1721423.5 after
11101compensating for the time zone difference. The built-in @kbd{t J} 11101compensating for the time zone difference. The built-in @kbd{t J}
11102command performs this conversion for you. 11102command performs this conversion for you.
11103 11103
11104The Julian day number is based on the Julian cycle, which was invented 11104The Julian day number is based on the Julian cycle, which was invented
11105in 1583 by Joseph Justus Scaliger. Scaliger named it the Julian cycle 11105in 1583 by Joseph Justus Scaliger. Scaliger named it the Julian cycle
11106since it is involves the Julian calendar, but some have suggested that 11106since it involves the Julian calendar, but some have suggested that
11107Scaliger named it in honor of his father, Julius Caesar Scaliger. The 11107Scaliger named it in honor of his father, Julius Caesar Scaliger. The
11108Julian cycle is based it on three other cycles: the indiction cycle, 11108Julian cycle is based on three other cycles: the indiction cycle, the
11109the Metonic cycle, and the solar cycle. The indiction cycle is a 15 11109Metonic cycle, and the solar cycle. The indiction cycle is a 15 year
11110year cycle originally used by the Romans for tax purposes but later 11110cycle originally used by the Romans for tax purposes but later used to
11111used to date medieval documents. The Metonic cycle is a 19 year 11111date medieval documents. The Metonic cycle is a 19 year cycle; 19
11112cycle; 19 years is close to being a common multiple of a solar year 11112years is close to being a common multiple of a solar year and a lunar
11113and a lunar month, and so every 19 years the phases of the moon will 11113month, and so every 19 years the phases of the moon will occur on the
11114occur on the same days of the year. The solar cycle is a 28 year 11114same days of the year. The solar cycle is a 28 year cycle; the Julian
11115cycle; the Julian calendar repeats itself every 28 years. The 11115calendar repeats itself every 28 years. The smallest time period
11116smallest time period which contains multiples of all three cycles is 11116which contains multiples of all three cycles is the least common
11117the least common multiple of 15 years, 19 years and 28 years, which 11117multiple of 15 years, 19 years and 28 years, which (since they're
11118(since they're pairwise relatively prime) is 11118pairwise relatively prime) is
11119@texline @math{15\times 19\times 28 = 7980} years. 11119@texline @math{15\times 19\times 28 = 7980} years.
11120@infoline 15*19*28 = 7980 years. 11120@infoline 15*19*28 = 7980 years.
11121This is the length of a Julian cycle. Working backwards, the previous 11121This is the length of a Julian cycle. Working backwards, the previous