HEBCAL(1)

NAME
hebcal - a Jewish calendar generator

SYNOPSIS
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

DESCRIPTION
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 1992
will print out the holidays occurring in October of 1992 C.E., while the command
	hebcal Tish 5752
will 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 help
at the command prompt.

OPTIONS

-8  Use 8-bit Hebrew (ISO-8859-8-Logical).

-a  Use Ashkenazis hebrew.

-c  Add approximate candle-lighting times. See below.

-d  Print the Hebrew date for the entire date range.

-D  Print the hebrew date for dates with some event.

-e  Change the output format to European-style dates: dd.mm.yyyy

-h  Suppress holidays in output. User defined calendar events are unaffected by this switch.

-H  When the -H switch is used, all dates specified on the command line are assumed to be hebrew dates. So for instance,

        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.

-i  Use the Israeli sedra scheme when used in conjunction with -S or -s. This has no effect if the -S or -s switches are unused.

-I file
    Read extra events from file. These events are printed regardless of the -h suppress holidays switch.
    There is one holiday per line in file, each with the format
    month day description
    where month is a string identifying the Jewish month in question day is a number from 1 to 30, and description is a newline-terminated string describing the holiday. An example might be
        Adar 1 Start cleaning kitchen for Passover.
        Adar 1 Start cleaning kitchen for Passover.

-l deg,min
    Set the latitude for solar calculations to deg degrees and min minutes. Negative values are south.

-L deg,min
    Set the longitude for solar calculations to deg degrees and min minutes. NOTE: Negative values are EAST longitude.

-o  Add the count of the omer to the output.

-r  Use a tab-delineated format, and somewhat terser strings. Instead of saying ' 13th day of the omer ' hebcal will say ' Omer: 13 '

-s  Add the weekly sedra to the output on Saturdays. See -i.

-S  Add the weekly sedra to the output every day. When this option is invoked, every time a day is printed, the torah reading for the Saturday on or immediately following that date is printed. If there is no reading for the next Saturday, then nothing is printed. See -i.

-t  Print calendar information for today's date only. -d and -o are asserted with this option.

-T  Same as -t, only without the gregorian date. This option is useful in login scripts, just to see what's happening today in the Jewish calendar.

-w  Add the day of the week to the output.

-y  Print only the last two digits of the year.

-Y file
    Read a table of yahrtzeit dates from file. These events are printed regardless of the -h suppress holidays switch.
    There is one death-date per line in file, each with the format
    month day year description
    where month, day and year form the gregorian date of death. description is a newline-terminated string to be printed on the yahrtzeit. An example might be
        12 29 1957 Menachem Mendel's yahrtzeit.
        5 15 1930 Benjamin's yahrtzeit.

CANDLE-LIGHTING TIMES
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 cities
at 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 DST
at the command prompt.

For a status report on customizations, type type
	hebcal info
at the command prompt.

EXAMPLES

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

ENVIRONMENT
Hebcal uses two environment variables:

HEBCAL_CITY
    Hebcal uses this value as the default city for sunset calculations. A list of available cities is available with from hebcal with the command:
    hebcal cities

HEBCAL_OPTS
    The value of this variable is automatically processed as if it were typed at the command line before any other actual command-line-arguments.

AUTHOR
Danny Sadinoff

SEE ALSO
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.

DIAGNOSTICS

hebcal help
    Prints a shorter version of this manpage, with comments on each option.

hebcal info
    Prints the version number and default values of the program.

hebcal DST
    Prints a list of available daylight savings time schemes, suitable as arguments to the -Z DST option.

hebcal cities
    Prints a list of cities which hebcal knows about, suitable as arguments to the -C city option. If your city does not appear on this list, put the necessary defaults in the DST_OPTS
     environment variable.

hebcal copying
    Prints the GNU license, with information about copying the program. See below.

hebcal warranty
    Tells you how there's NO WARRANTY for hebcal.

DISCLAIMER
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.

BUGS
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, e.g. before the 1752 in Britain and before circa 1918 in Russia. See the wikipedia entry for "Daylight saving time" for a splendid chart depicting when the changeover from the Julian to the Gregorian calendars occurred 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.

BUG REPORTS TO
Danny Sadinoff
danny@sadinoff.com

COPYING
Copyright (c) 1994-2006 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.