C. Wingate: Most churches include Saturday night s...

C. Wingate: Most churches include Saturday night service (if they have one) attendance with Sunday morning attendances into the "Sunday attendance".

As a result, the Christmas effect occurs when Christmas Eve falls on a Sunday or a Saturday. Going from a non-CE year to a CE year, the fall is blunted, e.g., 2004 to 2005. Going from a CE year to a non-CE year, the fall is accentuated, e.g, 2006 to 2007. Going from a CE year to a CE year, e.g., 2005 to 2006, or non-CE year to a non-CE year, their isn't a Christmas effect (apples to apples).