The "Millennium Countdown clock", dubbed "the Time in the Slime", was installed in the waters of the River Liffey in March '96 as a countdown to the year 2000. A postcard dispenser on O'Connell bridge printed the number of seconds to the millennium on a postcard at a cost of 20p. The clock and control box were removed in December 1996 after persistent technical problems.
The removal of the control box left a space in the bridge parapet. In 2004, pranksters took advantage of the space by installing a hoax commemorative plaque memorialising the totally fictitious "Father Pat Noise". The plaque was only noticed by the council in 2006 and has reappeared after every attempt to remove it since.