Hi G,
I dunno, why is everyone on the planet now going by the Christian calendar? Even Muslims? Ask a Chinese or a Jew what year it is. 2005 A.D. they'll say.
I don't know where you got this information from, but it is inaccurate.
Muslims do not subscibe to the Christian dating system. Muslims take their date from the time of Muhammad's migration from Mecca to Medina, a journey referred to as 'hijrah'. Their system uses AH (after hijrah) and not AD.
Chinese have a calendar going way back thousands of years before the BC AD system was invented. They have a year of the monkey, dragon, rabbit etc, but no year of Jesus.
Jews also do not subscribe to the Christian system, why on Earth would they?
The date today for Jews is '1st of Sivan, 5765',
here is a link to a converter from Jewish date to Gregorian.
I think you will also find that B.C. and A.D. are slowly going out of use, and are being replaced by the more politically correct BCE and CE.
Brian.
™ Version 4.2