as-salamu alaykom, I have been doing some research about the possibility of adding hijri calendar directly into glibc. I found that glibc does support other calendars, such as Buddhist Era (using in Thailand, and Laos I think) and the Japanese Emperors' reigns.
That is done by adding definitions for era, era_d_t_fmt, era_d_fmt, era_t_fmt, and alt_digits in the locale [1]. Those definitions modify the behaviour of some time functions (such as strftime) when E and O modifiers are used [2]. The format of 'era' consists of semicolon-separated strings. Each string shall be an era description segment with the format: direction:offset:start_date:end_date:era_name:era_format The descriptions for each field are in [1]. Now the problem is that supported calendars are those which are based on Gregorian calendar. In [3] it says: The E modifier supports alternative date formats, such as the Japanese Emperor's Era, as long as these are based on the Gregorian calendar system. Extending the E modifiers to other date elements may provide an implementation-defined extension capable of supporting other calendar systems, especially in combination with the O modifier. So, I was thinking, that this 'era' can be used for Hijri as follows: 1. For countries that formally use Hijri system, we can add an 'era' definition in their respective locale files. The era field that matters now is 'era_name'. It can be something like "A.H." or even "ه". 2. In glibc C code: a conversion function from Gregorian to Hijri can be added, I was thinking of using the conversion functions that implement the Um-Ul-Qura algorithm since, as far as I know, this is the algorithm that is formally used in Arabia. 3. Somewhere in glibc's time/strftime_l.c & time/strptime_l.c [4], the code should check if era_name is "A.H" or "ه", if that is true, it will call for the conversion function to get the appropriate Hijri date. I hope to get your comments on this suggestion. [1] http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap07.html#tag_07_03_05 [2] http://www.gnu.org/software/libc/manual/html_node/Formatting-Calendar-Time.html#Formatting-Calendar-Time [3] http://www.opengroup.org/onlinepubs/009695399/utilities/date.html [4] http://sources.redhat.com/cgi-bin/cvsweb.cgi/libc/time/strftime_l.c?cvsroot=glibc & http://sources.redhat.com/cgi-bin/cvsweb.cgi/libc/time/strptime_l.c?cvsroot=glibc -- أحمد المحمودي (Ahmed El-Mahmoudy) Digital design engineer GPG KeyID: 0x9DCA0B27 (@ subkeys.pgp.net) GPG Fingerprint: 087D 3767 8CAC 65B1 8F6C 156E D325 C3C8 9DCA 0B27 _______________________________________________ Developer mailing list [email protected] http://lists.arabeyes.org/mailman/listinfo/developer
