The worry is that computers still working with old COBOL or FORTRAN software will misread all those nines as permission to stop everything in its tracks.
Most technology experts agree that the 9999 bug will not bite.
—Murray Campbell, “Today’s 9999 glitch a drill for Y2K bug,” The Globe and Mail, September 9, 1999
“It’s an interesting issue because it has not got the publicity or board-level attention that Y2K has. It also hasn’t got the budget and is something many people have just woken up to during the last few months,” he said.
Compared to Y2K, though, the 9999 bug would be a “non-event” as it only affected old mainframe systems, Mr Balboni said.
—Mandy Bryan, “Screening at local terminal 9999,” Australian Financial Review, September 6, 1999
—“DGD,” AAP Newsfeed, June 26, 1998
Y2K leap year bug