praytime - produce Islamic prayer time schedule
SYNOPSIS
praytime [-h] [-i] [-f fiqh] [-r ratio] [-a angle] [-t time]
[-m time] [ [month] year ]
DESCRIPTION
praytime generates Islamic prayer time schedules and
computes the direction of the Qiblah for any location. If
no argument is given, the prayer time schedule for the
current date at the default location is produced. (The
default location is the location specified by appropriately
setting the PTLOC environment variable (see below). If
PTLOC is not set, the location configured into the program
when it was compiled is used.) If a year is specified, the
program outputs a schedule for the entire year. If a month
is also specified, a schedule just for that month is
printed. If the -h option is specified, praytime takes the
given month/year as a Hijri month/year (see Hdate/Hcal (1L))
and produces a schedule accordingly.
The year can be between 1900 and 2200, or 0 for a
"perpetual" schedule. (Hijri year can be between 1318 and
1625.) The month is a number between 1 and 12. Times in a
"perpetual" schedules are essentially the average for the
four years of a leap cycle. (The yearly variation in prayer
times is seldom more than two minutes, and the times return
back to almost the same value every four years.)
praytime allows for Fiqhi variations in computing methods.
The following command line options affect the method of
computation.
- -f fiqh
- Fiqh should be S(Hafi'i) or H(anafi). Sets the
shadow ratio for determining 'Asr to 1 or 2,
respectively. Default value is SHafi'i.
- -r ratio
- Specifies the value of the 'Asr shadow ratio
explicitly. Default value is 1.
- -a angle
- Specifies Sun's angle of depression at Fajr in
degrees. Common values are 18 (for Fajr to be the
same as the astronomical twilight) or 15 (a bit
later). Default value is 18, which many hold to be
the correct value and which is also the value
adopted by most Islamic countries today. In North
America, the practice has been to use a depression
angle of 15. However, in general, extreme care
should be employed in this regard and very reliable
observational data should be required to accept any
value which is less than 18 degrees. The morning
twilight marks the beginning of the fasting period
in RamaDHaan, and as such, using smaller values for
the depression angle may even nullify the Fast.
- -m time
- Specifies a maximum time interval from Fajr to
sunrise in minutes. A common value used is 90
minutes. This method is sometimes used in high-
latitude locations where times for the usual values
of Sun's depression are undefined or are
impractical for certain days during the year.
- -t time
- Specifies a fixed time interval from Fajr to
sunrise in minutes. This value is used to compute
daily time for Fajr prayers. A common value used
is 90 minutes. This method is sometimes useful in
extremely high-latitude locations where times for
the usual values of Sun's depression are either
undefined or are impractical.
Note: 'Isha is computed symmetrically with respect to Fajr,
with whichever method is chosen and whatever parameter value
is specified. It is an error to specify at the same time
both -a and -t or both -t and -m or both -f and -r.
To generate schedules for locations other than the location
configured into the program, set the PTLOC environment
variable appropriately (in your .login file under UNIX or
autoexec.bat under DOS) or use the following command line
option.
- -i
- reads name and geographical data for the location
from the standard input, instead of using the
default location. If standard input is a
(terminal) keyboard, praytime prompts the user for
the values.
LOCATION DATA
Data supplied through the environment variable PTLOC or via
standard input must contain (in given order):
- Name of location (up to 40 characters)
- Latitude degrees and minutes, and N or S to specify
north or south.
- Longitude degrees and minutes, and E or W to specify
east or west.
- Time Zone in hours (Decimal for fractional hour zones,
negative if West of Greenwich).
Y or 1 if Daylight Saving Time adjustment needed. N or
0, otherwise.
Data items should be separated by whitespace. Input may
contain data for more than one location; the tables will be
concatenated on the output.
EXAMPLES
The following example produces a prayer time schedule for
August 1994.
praytime 8 1994
The following command produces a schedule for RamaDhaan
1414.
praytime -h 9 1414
The following command produces a schedule for the year 1994,
using the value 15 for the sun's the angle of depression.
praytime -a 15 1994
The following command sequence produces a schedule for the
year 1994 for Washington, DC.
If need be, set the PTLOC environment variable
export PTLOC="Washington, DC 38 54 N 77 2 W -5 Y"
Then execute:
praytime 1994
The following command sequence on produces a perpetual
prayer schedule for Washington, DC, using the sun's
depression angle of 15 degrees to define Fajr and a shadow
ratio of 2 to define 'Asr. The schedule includes adjustment
for Daylight Saving Time.
cat > dc.dta
Washington, DC 38 54 N 77 2 W -5 Y
^D
Then execute:
praytime -i -a15 -r 2 0 < dc.dta
BUGS
praytime does not correctly handle Daylight Saving Time outside of the United States, As
a quick hack, this can be fixed by adding an extra hour to your distance from GMT.
SEE ALSO
hdate/hcal (1L), premind(1L)
AUTHORS
Original program, called `praytimer', produced time
schedules in TeX and was derived by Kamal Abdali from his
Minaret program for the Macintosh. Waleed Muhanna
(wmuhanna@magnus.acs.ohio-state.edu) modified the program to
remove all TeX related code; to improve input checking, to
allow a default location to be easily configured in; to
permit the user to print a schedule for the current date or
a specified month and year; and to integrate it with
hdate/hcal. Waleed Kadous (waleed@cse.unsw.edu.au) ported the code to the BeOS