Instructions for Printable & Mental Perpetual Gregorian Calendar By: Rufus F. Kiser PDHB Rufus F. Kiser PDHB has worked in many different vocations, including retail, wholesale, and factory work. He lived on a farm until age 20, and is interested in alternative energy sources and studying the most efficient ways of utilizing them. He intends his book to be a valuable resource for those interested in the Gregorian calendar and its applications to areas such as bookkeeping, budgeting, and countless others.