The Opportunity of a Millennium

y now you have probably heard more than you really care to about the " millennium crisis, " also known as the Year 2000 problem or—license plate style —Y2K. If you haven't brushed off the whole thing altogether, you've probably included in your New Year's resolution plan for January 1, 2000, to wait a little before rushing to the airport, stepping into an elevator, or cashing in on your mutual funds. Yet for all the books, conferences, and articles, the software community, with a few exceptions, has neither heeded the lesson nor seized the opportunity. But it may not be too late. For most companies, " doing something about Y2K " has usually involved sending stern letters to suppliers asking them to guarantee compliance of their products, and appointing a team—inter-nal or external—to convert existing software. Conversion here usually means going through old code, typically Cobol, looking for explicit uses of two-digit date fields, and extending them to four digits. If this characterizes the extent of your Year 2000 effort, your company is missing an important opportunity. How did the crisis happen in the first place? Conventional wisdom suggests that programmers were byte hoarders, who foolishly chose to save tiny amounts of memory instead of properly planning. An alternative explanation puts the blame on the programmers' managers, which is consistent with the current Dilbertist trend that suggests all managers are morons. Both these variants lack perspective. It is easy today to laugh at a programmer or a manager for saving two bytes of memory per database field in 1965. But we aren't the ones who had to make the tough technical decisions back then. Software construction, like other engineering efforts, is a constant search for the right trade-offs between a number of competing factors, including space efficiency, time efficiency, flexibility and maintainability of the architecture, compatibility, ease of use, and ease of implementation. One person's brilliant trade-off may become, in different cir-cumstances—say if memory costs drop a thousand-fold and a product meant to be used for two years lasts well into the next millennium—a paragon of silliness mocked in Newsweek cartoons. The two-digit date field may in many cases have been a silly choice, but it is just a choice among millions that programmers have to make all the time, not because they or their managers are cretins with no long-term vision, but because that's what their job takes. While …