Amid discarded coffee cups, mounds of paper and blinking screens, tired staff at Ulster Bank last night completed their euro changeover programme.

Many staff have been working on the project for the last two years, last week giving up holidays and even New Year's Eve celebrations for the sake of the new currency, which makes its debut on the international markets today.

Technical staff have been getting used to 12-hour days and seven-day weeks as part of the programme, which involved entirely changing the bank's accounting and trading systems.

This morning the bank holds its breath, hoping there are not too many glitches as the market puts the euro through its paces.

While most of the work was technical in nature, involving long hours in front of computer screens, staff in the bank's four divisions were happy to give the long hours over the weekend, according to Mr Pat McArdle, head of EMU planning at Ulster Bank.

"Many of them have been working on this for the last two years and were committed to it, so they did not mind coming in and finally seeing it reach completion," he said.

One of the tasks from today at the bank will be to throw out all the bulky euro changeover manuals which have accumulated in the bank's headquarters on George's Quay in Dublin.

"The whole idea now is to go into a new era, to turn over a new sheet," said Ms Ellvena Graham, head of IT, Ulster Bank Group Treasury.

She was spending the last few hours yesterday doing some final checks and seeing that everything was ready for this morning.

While one of the biggest tasks was changing the central accounting system in the treasury section, Ms Graham said when the conversion rates were announced on Thursday the pace significantly increased.

"Up to that we had been doing rehearsals, but not with the actual figures, so when they came in, we really had to go for it," she said.

Many sections in the bank balance their books for the year at this time anyway, so the euro preparations had to take place alongside this, she added.

Another task was to check all payments leaving the bank's treasury division this morning.

"Each payment has to be checked individually. There is no margin of error. If the conversion is done wrongly, that could mean losing a lot of money," she said.

Mr Sean Hawkshaw, head of business development and special projects at the bank's investment division, said the changeover there involved several thousand individual tasks.

On New Year's Eve, 30 employees worked through the night to convert the 500 investment portfolios managed by the division. The late-night working environment was made less conducive, said Mr Hawkshaw, when the air conditioning system broke down. "The heat from the photocopiers and the PC screens meant a few people got frazzled, but we got there in the end," he said.

Mr Hawkshaw used the bank's intranet (an internal Internet service) system to see what progress each staff member was making with their tasks. Equally important was the section on the intranet giving details of the bank's "post-EMU bash" which was in full swing last night.