during what celebration is this ball dropped?
New Year's Eve celebration
Times Square Ball
The Times Square Ball is a time ball located in New York City's Times Square. Located on the roof of One Times Square, the ball is a prominent part of a New Year's Eve celebration in Times Square commonly referred to as the ball drop, where the ball descends down a specially designed flagpole, beginning at 11:59:00 p.m. ET, and resting at midnight to signal the start of the new year. In recent years, the festivities have been preceded by live entertainment, including performances by musicians.
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Times Square Ball [SEP] Introduction
First held on December 31, 1907, to welcome 1908, the ball drop has been held annually since, except in 1942 and 1943 in observance of wartime blackouts. The ball's design has been updated over the years to reflect improvements in lighting technology; the ball was initially constructed from wood and iron, and lit with 100 incandescent light bulbs. The current incarnation features a computerized LED lighting system and an outer surface consisting of triangular crystal panels. These panels contain inscriptions representing a yearly theme. Since 2009, the current ball has been displayed atop on Times Square year-round, while the original, smaller version of the current ball that was used in 2008 has been on display inside the Times Square visitor's center.