Nls_calendar='Arabic Hijrah'

Question

Hi All,
Is any one using nls_calendar='Arabic Hijrah'? Its working fine but the only problem that we are facing is, oracle shows arabic date which is exactly less than one day of arabic date. i.e. if arabic data is 14th, oracle shows 13th. Any one have idea about this? I heard the same problem from so many people, is there any solution for this.
thanks in advance

Answer 1

Arabic Hijrah Calendar - FAQ
CONTENTS
1.How to set Calendar to "Arabic Hijrah" ?
2.How to display both Hijrah and Gregorian dates in the same select statement?
3.What is Calendar Deviation?
4.How to set deviation?
5. Adding ONE day in the lxecal.nlt gives TWO days added. How to workaround?
Questions & Answers
1.How to set Calendar to "Arabic Hijrah" ?
Answer
Set NLS_CALENDAR parameter in one of the following ways:
1. In the Current session :
SQL> alter session set NLS_CALENDAR="Arabic Hijrah" ;
2. All applications for a specific client:
Set NLS_CALENDAR Variable in client OS environment.
<e.g: On NT: set variable in the registry
On Unix: set UNIX environment variable in .profile/.cshrc>
3. Within SQL function:
SQL> select to_char(sysdate,'day dd month yyyy','nls_calendar=''arabic hijrah''')
from dual ;
References
Note 30772.1 Init.ora Parameter "NLS_CALENDAR" Reference Note
2.How to display both Hijrah and Gregorian dates in the same select statement?
Answer
select
to_char(sysdate,'day dd month yyyy','nls_calendar=''Arabic Hijrah'''),
to_char(sysdate,'day dd month yyyy','nls_calendar=''English Hijrah'''),
to_char(sysdate,'day dd month yyyy','nls_calendar=''gregorian''')
from dual ;
to make things a bit more clear:
alter session set nls_calendar = 'Arabic Hijrah';
gives the names of the Hijrah months in Arabic
so you client needs to be configured to display Arabic. -> Note 179133.1
alter session set nls_calendar = 'English Hijrah';
gives the names of the Hijrah months in english.
alter session set nls_calendar = 'gregorian';
gives the names of the Gregorian months (jan-feb-etc).
If you want the names of the Gregorian months in Arabic then please
see Note 264280.1 Incorrect NLS_DATE_LANGUAGE for Arabian Countries
References
Bug 1302683
3.What is Calendar Deviation?
Answer
Since Hijrah month is based on the moon complete revolution around the sun, Hijrah
Calendar has different number of days in a year than Gregorian; therefore some manual
deviation adjustement might be needed for the conversion to/from Gregorian. In other
words HIJRAH calendar is Lunar based, corrections need to be made every so often.
Note 130551.1 Conversion Algorithm of Gregorian Date to Arabic (Hijra) Date
4.How to set deviation?
Answer
1. Shutdown the database
2. Edit/create lxecal.nlt (lxecal.dat in Oracle7) in
for Oracle 8 up to 9i $ORACLE_HOME/ocommon/nls
for Oracle 10g and up $ORACLE_HOME/nls
In 8i and 9i you a example file in the 'demo' directory $ORACLE_HOME/ocommon/nls/demo
In 10g this demo file is not shipped, you can simply create on or copy the demo file from
a 9i or 8i installation.
This example makes the known adjustments needed between Gregorian
years 2000 and 2004:
DEFINE calendar
calendar_name = "Arabic Hijrah"
deviation_data = {
<"MAY-05-2000 ad">:1
<"AUG-30-2000 ad">:1
<"NOV-26-2000 ad">:11
<"JAN-25-2001 ad">:11
<"Feb-24-2001 ad">:1
<"MAR-25-2001 ad">:11
<"JUN-22-2001 ad">:1
<"JUL-21-2001 ad">:11
<"AUG-20-2001 ad">:1
<"OCT-17-2001 ad">:1
<"NOV-15-2001 ad">:11
<"JAN-14-2002 ad">:11
<"FEB-13-2002 ad">:1
<"MAR-14-2002 ad">:11
<"OCT-07-2002 ad">:1
<"NOV-05-2002 ad">:11
<"DEC-05-2002 ad">:1
<"JAN-03-2003 ad">:11
<"FEB-02-2003 ad">:1
<"JUN-30-2003 ad">:11
<"JUL-30-2003 ad">:1
<"AUG-28-2003 ad">:11
<"SEP-27-2003 ad">:1
<"JUN-18-2004 ad">:11
<"JUL-18-2004 ad">:1
<"AUG-16-2004 ad">:11
<"SEP-15-2004 ad">:1
<"OCT-14-2004 ad">:11
ENDDEFINE calendar_deviation
ENDDEFINE calendar
Notes: * Gregorian date specified in the deviation should correspond to one of
29th, 30th or 31th days of the hijrah calendar.
* Numbers greater than 10 are used to subtract days, e.g:
11 --> subtract one day, 12 --> subtract two days ...etc
3. Run the NLS Calendar Utility lxegen to register your modification to Oracle calendar
system, this utility generates lxecalah.nlb file in the same directory mentioned above.
4. startup the database.
If you want to substract dates, please also see to
Bug 2215017 SUBTRACTING DAYS FROM ARABIC HIJRA DATE DOES NOT WORK
For 9i this bug is logged:
Bug 2749165 NOT ABLE TO ADJUST THE HIJRAH CALENDAR ANYMORE IN 9.X
You need Patch 9204 or higher to be able to adjust the calendar.
There are also these backports:
windows NT/2000 9.2.0.3 Patch2. / patch set nr 2973634
HP-UX 64 bit 9.2.0.3 / Patch nr 2749165
This is also fixed in 10g and up
5. Adding ONE day in the lxecal.nlt gives TWO days added. How to workaround?
Answer
SQL> alter session set nls_calendar = 'Gregorian';
SQL> select d from d;
D
07/06/05
08/06/05
SQL> alter session set nls_calendar = 'English Hijrah';
SQL> select d from d;
D
29 Rabi' Thani 1426
01 Jamada El Oula 1426
07/06/05 needs to be 30 Rabi' Thani 1426
so you add this to the lxecal.nlt
     DEFINE calendar
calendar_name = "English Hijrah"
     DEFINE calendar_deviation
deviation_data = {
                         <"Jun-07-2005 ad">:1
ENDDEFINE calendar_deviation
ENDDEFINE calendar
and run lxegen
SQL> select d from d;
D
01 Jamada El Oula 1426
02 Jamada El Oula 1426
* the date is now 2 days further!!! this is due rounding problems in the algorithm
used for the calendar conversion a workaround is to substract FIRST one day in lxecal.nlt
     DEFINE calendar
calendar_name = "English Hijrah"
     DEFINE calendar_deviation
deviation_data = {
                         <"Jun-07-2005 ad">:11
                         <"Jun-07-2005 ad">:1
ENDDEFINE calendar_deviation
ENDDEFINE calendar
and run lxegen, this gives:
SQL> select d from d;
D
30 Rabi' Thani 1426
01 Jamada El Oula 1426
make sure that you substract first (= ":11") and then add (= ":1")
in the lxecal.nlt for the date
References
Oracle8i National Language Support Guide
these 2 bugs, both closed as "not a bug":
Bug 583924 NLS:HIJRAH CALENDAR DEVIATION DOES NOT WORK PROPERLY
Bug 2215017 SUBTRACTING DAYS FROM ARABIC HIJRA DATE DOES NOT WORK
Bug 2964132 TO_DATE GIVES ORA-01841 WITH HIJRAH CALENDAR
will be fixed in 10gR2
Note 130551.1 Conversion Algorithm of Gregorian Date to Arabic (Hijra) Date
Note 264280.1     Incorrect NLS_DATE_LANGUAGE for Arabian Countries
http://www.math.nus.edu.sg/aslaksen/calendar/islamic.html
The Umm al-Qura Calendar of Saudi Arabia
http://www.phys.uu.nl/~vgent/islam/mecca/ummalqura.htm
Note 241047.1 The Priority of NLS Parameters Explained.
Note 158577.1 NLS_LANG Explained (How does Client-Server Character Conversion Work?)
Note 179133.1 The correct NLS_LANG in a Windows Environment
For further NLS / Globalization information you may start here:
Note 267942.1 Globalization Technology (NLS) Knowledge Browser