church calendar: a calendar of the Christian year indicating the dates of fasts and festivals
gregorian calendar: the solar calendar now in general use, introduced by Gregory XIII in 1582 to correct an error in the Julian calendar by suppressing 10 days, making Oct 5 be called Oct 15, and providing that only centenary years divisible by 400 should be leap years; it was adopted by Great Britain and the American colonies in 1752
transfusion reaction: reaction of the body to a transfusion of blood that is not compatible with its own blood; an adverse reaction can range from fever and hives to renal failure and shock and death