Abstract: A method of modifying existing computer software and databases to utilize a date representation which accommodates dates subsequent to Dec. 1, 1999 but preserves the desirable properties of utilizing no more than six numeric characters, is sortable in calendar date order and can be visually interpreted by a human being. The date is represented as CYYDDD, wherein C is indicative of the century, YY is indicative of the year and DDD is indicative of the Julian Day. The software programs which represent or manipulate date information are modified to accommodate this format. The process can be performed by computer to yield converted computer systems which are products of the process.