[NYer]

This seems to be att odds with other things I have read about why December 25 is the day designated as Christ's birthday by the Roman Catholic church. So which is the real reason?

You don't cite the other sources; hence it is not possible to compare authoriship. Since the information posted in this thread, dates back to the 4th century and was provided by a Catholic historian, it seems to promote a solid background.

[jkl1122]

Just curious. Since the Biblical record doesn't match up very well with the date of December 25, it makes sense that the date comes from secular sources.