Multi calendar system for pgsql

Hi everyone,
I want to try to add a multi calendar system for pgsql. I want to know if it
will be accepted as a patch to pgsql?

More details:
Multi calendar systems are useful for several languages and countries using
different calendar: Hijri, Persian, Hebrew, etc.
For implementation I think it is better to add this support in date fields
like this:
create table tb (dt date calendar persian);
if no calendar is defined, it will be Gregorian so no problem is made for
old sql commands.

I am new in pgsql dev but if I know this patch will be accepted, I am happy
to work on it.
Regards,
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__ \ /_\\_-//_ Mohsen Alimomeni

--
__ \ /_\\_-//_ Mohsen Alimomeni