| HEBCAL(1) | General Commands Manual | HEBCAL(1) |
hebcal - a Jewish calendar generator
hebcal [ -8acdDehHiorsStTwy ]
[ -I input_file ]
[ -Y yahrtzeit_file ]
[ -C city ]
[ -l latitude -L longitude]
[ -z timezone ]
[ -Z daylight_savings_scheme ]
[[ month [ day ]] year ]
hebcal help
hebcal info
hebcal DST
hebcal cities
hebcal copying
hebcal warranty
With no arguments, hebcal will print to stdout the dates of the Jewish holidays in the current secular year. Each line is prefixed with a gregorian date of the form mm/dd/yyyy.
By specifying month, day, or year, output can be limited to a particular month or date in a particular year. Note that year is usually a four-digit integer, So 92 is during the Roman period, not the late twentieth century. In if the hebrew dates option is turned on, this number represents th Jewish calendar year. month is a number from 1..12, or the name of a Jewish calendar month.
day is a number from 1..31.
For example, the command
hebcal 10 1992will print out the holidays occurring in October of 1992 C.E., while the command
hebcal Tish 5752will print dates of interest in the month of Tishrei in Jewish calendar year 5752.
NOTE: hebcal 92 is not the same as hebcal 1992. The year is assumed to be complete, so the former calendar preceeds the latter by nineteen centuries.
A few other bells and whistles include the weekly sedra as well as the day of the week, the count of the omer, and the Hebrew date.
Output from hebcal can be used to drive calendar(1). Day-to-day use for hebcal is provided for in the -T and -t switches, which print out Jewish calendar entries for the current date.
To get a quick-reference on-line help, type
hebcal helpat the command prompt.
example% hebcal -H 5754
will print data for 5754, Starting in Tishrei, and ending in Elul. Hebcal is smart enough to detect a Hebrew month and infer that you want a Hebrew date range, so you could type
example% hebcal tish 5754
The -H switch would be superfluous in this case. Invoking hebcal with just the -H switch by itself will print data for the current Hebrew year, starting in Tishrei.
12 29 1957 Menachem Mendel's yahrtzeit.
5 15 1930 Benjamin's yahrtzeit.
Hebcal's candlelighting times are only approximations. If you ever have any doubts about it's times, consult your local halachic authority. If you enter geographic coordinates above the artic circle or antarctic circle, the times are guaranteed to be wrong.
Hebcal contains a small database of cities with their associated geographic information and time-zone information. The geographic and time information necessary to calculate sundown times can come to hebcal any of three ways:
1) The default: the system manager sets a default city when the
program is compiled.
2) Hebcal looks in the environment variable HEBCAL_CITY for the name of
a city in hebcal's database, and if it finds one, hebcal will make that the
new default city.
3) 1 and 2 may be overridden by command line arguments, including those
specified in the HEBCAL_OPTS environment variable. The most natural
way to do this is to use the -c city command. This will
localize hebcal to city. A list of the cities hebcal knows about can
be obtained by typing
hebcal citiesat the command prompt. If the city you want isn't on that list, you can directly control hebcal's geographic information with the -l, -L -z and -Z DST switches. Note that changing the geographic coordinates causes the timezone to default to Zulu and the daylight savings time processor to default to 'none.' To get a list of possible values for DST, type
hebcal DSTat the command prompt.
For a status report on customizations, type type
hebcal infoat the command prompt.
To find the days of the omer in 1997, printing the days of the week:
example% hebcal -how 1997
4/23/97 Wed, 1st day of the Omer
4/24/97 Thu, 2nd day of the Omer
4/25/97 Fri, 3rd day of the Omer
.
.
.
6/9/97 Mon, 48th day of the Omer
6/10/97 Tue, 49th day of the Omer
To print only the weekly sedrot of Nisan 5770
example% hebcal -hs Nisan 5770
3/20/2010 Parashat Vayikra
3/27/2010 Parashat Tzav
4/10/2010 Parashat Shmini
To find out what's happening in the Jewish calendar today , use
example% hebcal -TS
19 of Nisan, 5752
Parshat Achrei Mot
Pesach V (CH"M)
4th day of the Omer
Hebcal uses two environment variables:
Danny Sadinoff
calendar(1), emacs(1), hcal(1), hdate(1), omer(1), remind(1), rise(1)
The latest version of the code will be available from http://sourceforge.net/projects/hebcal
The original motivation for the algorithms in this program was the Tur Shulchan Aruch.
For version 3, much of the program was rewritten using Emacs 19's calendar routines by Edward M. Reingold and Nachum Dershowitz. Their program is extremely clear and provides many instructive examples of fine calendar code in emacs-LISP.
A well written treatment of the Jewish calendar for the layman can be found in Understanding the Jewish Calendar by Rabbi Nathan Bushwick. A more complete bibliography on the topic can be found there, as well as in the Encyclopedia Judaica entry on the calendar.
This is just a program I wrote during summer school and while avoiding my senior project. It should not be invested with any sort of halachic authority.
Hebrew dates are only valid before sundown on that secular date. An option to control this will be added in a later release.
Negative longitudes are EAST of Greenwich.
Some combinations of options produce weird results, e.g.
hebcal -dH nisan 5744
hebcal -dH 5744
This comes into play when you use the ENV_OPT environment variable.
The sunup/sundown routines aren't accurate enough. If you enter geographic coordinates above the artic circle or antarctic circle, the times are guaranteed to be wrong.
Hebcal only translates between the Gregorian calendar and the Jewish calendar. This means that the results will be at least partly useless where and when the gregorian calendar was not used, i.e. before the 1752 in Britain and before circa 1918 in Russia. See the wikipedia entry for a splendid chart of the changeover from the Julian to the Gregorian calendars in various places.
Hebcal cannot handle date computations before 2 C.E. sorry.
Daylight-Savings time rules are as up-to-date as a nonpaying job allows. US DST rules are correct only back to 1966.
Hebcal assumes that the Energy Policy Act of 2005, which changes the DST rules in the US will go into effect, even though congress may still revert it.
Danny Sadinoff
danny@sadinoff.com
Copyright (c) 1994-2004 Danny Sadinoff
Portions Copyright (c) 2002 Michael J. Radwin. All Rights Reserved.
Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies.
Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one.
Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this permission notice may be included in translations approved by the Free Software Foundation instead of in the original English.
For a full text of the copyright and lack of warranty information,
type
hebcal copying
or
hebcal warranty
at the command line.
| Hebcal Version 3.5 | Danny Sadinoff |