Common year starting on Friday has only one Friday the 13th; The only Friday the 13th in this common year occurs in August. Leap years starting on Thursday share this characteristic, but also have another one in February. This is the only year type where the "n"th "Doomsday" (this year Sunday) is not in ISO week "n"; it is in ISO week "n"-1. In the (currently used) Gregorian calendar, the fourteen types of year (seven common, seven leap) repeat in a 400-year cycle (20871 weeks). Forty-three common years per cycle or exactly 10.75% start on a Friday. The 28-year sub-cycle does only span across century
Friday the 13th (franchise) who had discovered the "Necronomicon". There have been two books released chronicling the making of the "Friday the 13th" films. In February 2005, FAB Press published their book containing interviews with the cast and crew of the "Friday the 13th" series of films. David Grove, a film journalist who has written for "Fangoria", "Cinefantastique", and various other British magazines detailing the creation of the "Friday the 13th" films, wrote the comprehensive book, "Making Friday the 13th: The Legend of Camp Blood". Grove interviewed over 100 "key personnel involved in making the films" to collect "detailed production histories of each of