Only two months after the world breathed a collective sigh of relief over the non-event of Y2K, computers are experiencing one last glitch related to the Millennium Bug: Feb. 29.

Today is Leap Day, that extra day added every four years to compensate for an imperfect calendar. But during years that end in "00," the rule is suspended -- unless the year is divisible by 400. So 2000 is in fact a leap year, but 1900 is not.

Computers have long had difficulty in leap years, treating Feb. 29 as March 1, or March 1 as Feb. 30. This year's "exception to an exception" seems to have compounded the confusion, forcing computers to shut down.

In Japan, where leap day has already arrived, some computer problems are being reported after some computers mistook today for March 1 and others simply failed to work.

Meteorological stations started spewing out erroneous data and 1,300 post office cash machines stopped working. Thousands of financial data terminals run by the Toyko Stock Exchange also included errors.

There have been glitches in other countries, but no real problems reported in Canada.

Computer industry experts say most programmers knew about the year 2000 exception and compensated for the problem during their Y2K preparations, when they ensured that computers didn't mistake Jan. 1, 2000 for Jan. 1, 1900