A computer glitch long predicted to disrupt global computer systems tomorrow, Infinity Day (9/9/99), is now expected to have little impact.

It was hoped that Infinity Day, where September 9th is represented as 9999 on many computer software programmes, might offer a glimpse of the millennium bug's effect.

Now experts say a major disruption is highly unlikely. Mr Alec Florence, of Priority Data Systems, in Dun Laoghaire, Co Dublin, says: "I don't believe there will be major disruptions. The infinity date doesn't work in the same way as the rollover to 2000. Most companies have conducted their Y2K programmes, and the products used would have included checks for the infinity date."

Mr Florence says his anti-virus software firm has received few queries about the expected glitch.

IT research specialist, Gartner Group, says it has identified only two cases of 9/9/99 coding in extremely obscure systems. Mr Andy Kyte, analyst with Gartner Group and Y2K specialist, says the only worry raised by Infinity Day is that it may persuade companies with no Y2K programme in place that there is no need to worry.

The Infinity Day string of nines may have been applied in computer programmes for several reasons. According to Mr Patrick O'Beirne, a software quality consultant with Systems Modelling, it was often applied to mean a date value for "End of File". But the more likely latest possible date value is 31/12/99, he adds.

"If you do have a problem on 9/9/99 , you'll do your best to make sure nobody will hear about it, because it's just too embarrassing. It tells the world you have not checked your code properly yet as part of your Y2K project; that you have not done testing around commonly accepted key dates. If that gets out, you may as well walk around with a bell saying: `Unclean! Unclean!' " Mr O'Beirne says.