h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

question has been raised lately as to who first dated years with CE/BCE
http://www.answers.com/topic/common-era
raises the point of the latin equivalent Vulgaris
before the twentieth century The common language of scolars was latin. So instead of CE this might have been VE
references to it as such are noted in 1716 and 1825
it is presumed that the use of AD and BC were replaced sometime after the second world war in an effort to be deity-neutral in matters relating to the new state of Israel.
However like the metric system (which was supposed to be universal by now) The conversion has failed to take place except in sporadic locations.

I can see no reason to object to BC and AD, whatever your beliefs. Whether you think Christ was the Messiah or not, his supposed birthdate makes as good as a starting point for the calendar as any other. And it seems ridiculous to say "We're going to use the birthdate of Jesus Christ as the start of our calendar, but so as not to offend anyone we won't name it after him".

And of course someone will note that historical records
(for example the date of death of Herod the Great) prove that we are using the wrong year anyway.

That's why I said "supposed birthdate", as we don't know what year it was, or what part of the year. It seems most likely that it was summer, because "there were shepherds abiding in the fields, keeping watch over their flocks by night" and this only happens in the summer.

One source said that during the lambing season ie Apr.- May the shepherds did not bring the sheep into the fold but kept watch over them in the field. so that is another possibility.