Y2K, also known as the Year 2000 problem, was a computer programming issue that was expected to cause extensive havoc as the year changed from 1999 to 2000. The problem was related to the formatting and storage of calendar data for dates in and beyond the year 2000. Many computer systems used only two digits to represent the year, assuming that the first two digits were always "19." As a result, there was a concern that when the year 2000 arrived, these systems would interpret the "00" as 1900 instead of 2000, causing errors in calculations and potentially bringing down computer systems infrastructures, such as those for banking and power plants.

Despite widespread concern about the potential implications of this change, not much happened when the year 2000 arrived. The United States government passed the Year 2000 Information and Readiness Disclosure Act to prepare for the event and formed a Presidents Council that consisted of senior officials from the administration and officials from agencies like the Federal Emergency Management Agency (FEMA) . In actuality, the episode came and went with little fanfare.

In addition to its technological implications, Y2K has also been associated with fashion trends from the late 1990s to early 2000s. Y2K fashion provides nostalgic notes from this era, with maximalist silhouettes, bright color palettes, low-rise distressed denim, sunglasses indoors, midi skirts, layered tees, and other elements. The Y2K style has evolved over time, with young people using sites like TikTok and Depop to source their inspired outfits and blend styles from the earlier 1990s, early 2000s, and early 2010s.