e and programmers continued to use two-digit year field to save memory. How the problem continued Programmers of 1960s and 1970s assumed that these program would long be replaced with new ones before the turn of the century. Though the computer hardware has come a long ways in past 30 years, the mainframe machine is still with us – only faster and able to run old programs cheaply. Many of these programs were written for a specific company to do a specific job and over the years more features have been added but little has changed at the core level, including two-digit dates. Scope of the problem Solving the problem, looking from the top, is as simple as telling the computer to change all existing dates to four digits and only to accept four-digits dates from now on. But few dates are easy to find in ‘date = MM/DD/YY format’. Many programmers used conventions such as "john – mary = sue" to calculate differences between two dates -– making it harder to find the date code if one is not familiar with the convention (3). But that is only the part of the problem. Over the years large amounts of data has been stored on disks and tapes and there are lots of duplicate data. In most part these data are stored in large files in a date sequence of collection. Many programs that handles these physical resources cannot handle four-digit year. Business applications that depends on these systems to figure out person’s age, length of unpaid invoices, interest due on bank deposits and so on are in for plenty of trouble. (14). Furthermore, many businesses have used date stamping –- a method that use embedded dates in the records. Date stamps are automatically placed on the record by the system in many transaction tracing systems. Brian Hayes in January/February 1995 American Scientist used the following examples to describe the date stamping problem: At the local dairy, the oldest milk on hand is supposed to...
