On this day, December 31st, in 1999, businesses across the world prepared for the Y2K disaster, where computer systems around the world were rumored to stop working at midnight.

Computer systems usually abbreviated year dates to only two digits. At the turn of the century, many people worried that the computer systems wouldn’t know how to adjust. An estimated $300 billion was spent preparing for the Y2K crisis in the United States. An additional $13 billion was spent in 2000 and 2001 in order to fix problems with the computer systems. Worldwide, an estimated $308 billlion was invested in Y2K bug fixes.

It was on this day, December 30th, in 1988 that Mercedes-Benz paid $20.2 million for failing to meet government fuel standards.

Mercedes-Benz’s first car was created by Karl Benz. The first petrol-powered car, called the Benz Patent Motorwagen, was patented by Benz in 1886. Later that year, Gottlieb Daimler converted the stagecoach to include a petrol engine with the help of engineer Wilhelm Maybach. The Mercedes-Benz brand name, however, was not introduced until 1926.

It was on this day, December 29th, in 1851 that the United States’ first YMCA opened in Boston, Massachusetts.

The Young Men’s Christian Association, or simply “the Y,” was founded in London, England in 1844. Captain Thomas Valentine Sullivan, American sailor and missionary, was influenced by the London YMCA and wanted to bring the organization to the United States. It was meant to serve as a home for British sailors that had landed in America. Now, there are more than 45 million members in the World Alliance of YMCAs.

It was on this day, December 28th, in 1912 that the first municipally owned streetcars became operational in San Francisco. These streetcars became an iconic part of the city.

The first cable car was patented by a San Francisco native, Andrew Smith Hallidie, in 1871. The cars were pulled by his patented cable, which ran between the rail tracks. Two years later, in 1873, Hallidie finished building his first rail track, and the car took its first trip down one of San Francisco’s historic hills.

On this day, December 27th, in 1932, Radio City Music Hall opened in New York City. The hall was originally meant to feature high-class variety shows.

On the night of the music hall’s opening, Ray Bolger, Doc Rockwell, and Martha Graham performed in a stage show. However, this format was not successful and the music hall was renovated just two weeks later. The shows afterwards all included a feature film combined with a stage performance.

It was on this day, December 26th, in 1933 that the FM radio was patented. Edwin Howard Armstrong’s patent came through as he was concurrently battling another inventor for the rights to the invention of superheterodyne radio.

Armstrong invented wide-band frequency modulation (FM) radio in a laboratory at Columbia University. His FM radio invention was different because it varied the frequency rather than varying the amplitude of a radio wave. This new technology eliminated “static,” which is a common problem with AM radio.

It was on this day, December 25th, in 1990 that the first successful trial run of the World Wide Web was completed.

The first web browser, World Wide Web, was completed by Tim Berners-Lee using a NeXT Computer. A NeXT Computer was also used to develop the first web server software, CERN httpd, in the world. However, the NeXT Computer technology was not successful on the market, and it was replaced by other technology soon thereafter.

On this day, December 24th, in 1893, Henry Ford completed his first successful gas motor.

Ford began working at the Detroit Electric Illuminating Company, where he learned about the new technology of the internal combustion engine. He took an early model of this engine home on Christmas Eve to show his wife. Using an electric light socket for power and his wife’s help for fuel administration, Ford started the engine that led him into a career with automobiles.

On this day, December 23rd, in 1970, the North Tower of the World Trade Center is opened. The completion earned the building the title of the tallest building in the world at the time with a height of 1,368 feet.

The North Tower held the title as the tallest building in the world for two years, but the Sears Tower surpassed it in 1973. However, the Tower retained the record for the greatest number of floors. The North Tower’s 110 floors was only surpassed in 2009 when the 163-floor Burj Khalifa was built in Dubai. The World Trade Center towers were a recognizable pair of skyscrapers on the New York City skyline, and the North Tower was distinguishable from its twin by the 360-foot-tall antenna atop its roof.

It was on this day, December 22nd, in 1851 that the first freight train is operated in India. In comparison, rail transportation began almost three decades earlier in the United States.

The first railroad in India was meant to haul construction materials. Then, the system developed in order to operate passenger rail lines. Passenger rails began operating in India in April 1853, which led to a bustling rail industry in the country. India now has the 4th largest rail network in the world. Annually, the country transports over 100 million tons of goods and 10 billion passengers.