Introduced by the Smithsonian Astrophysical Observatory in 1957 to track the orbit of Sputnik with a thirty-six-bit mainframe, to save on memory and compute resources by expressing time-coordinates in just eighteen-bits through 7 August 2576, the Modified Julian Date system simply dispatched with the proceeding two-million four-hundred-thousand days of history from the dawn of the calendar, counting backwards and resetting the number at noon on this day in 1858, often further truncated. This was also the reference epoch (see previously) for the earliest operating systems, chosen in part as it predated most modern record keeping. Because of the continual count, it is easier for software to process the intervening time elapsed between two events for applications like calculating interest, sell-by-dates for perishable inventories, etc, in the same was computers can’t really perform mathematical operations except by matrices. The Julian Period was proposed by sixteenth century academic Joseph Justus Scaliger (a year after the unrelated calendar was replaced in most of Europe by the Gregorian one) as the sum product of three calendrical cycles that comprise the system, twenty-eight solar cycles, nineteen lunar cycles and fifteen indiction cycles (the periodic census and tax reassessment of the Roman Empire that occurred every fifteen years)—or a span of seven thousand nine hundred and eighty years, reaching back in time under the assumption that all were synchronised at the beginning of time. Scaliger calculated this to be 4713 BC, well before any events in recorded history known to him.