Craigavon Shopping Centre made history in December 1994 when it opened its doors for the first time on a Sunday.
And, by all accounts, it was a great success.
Shoppers thronged to the centre and, with all the major stores open, a brisk trade was reported throughout the afternoon.
“All the traders were delighted with the response from the public,” said centre manager, Mr Harry Crooks.
“It was as busy as a normal Saturday for much of the time and everyone has voted the idea a resounding success.”
Craigavon Shopping Centre had never opened before on a Sunday but earlier in the year the centre carried out a survey of shoppers in order to gauge reaction.
“We were reacting to what has been going on at other centres throughout the country and we felt we had to do something to try and keep the trade in the area,” said Mr Crooks.
A small contingent from the Free Presbyterian Church staged a protest outside the centre handing out leaflets to people as they went in.