For most, the New Year brings new beginnings, hopeful opportunities, and resolutions.
For programmers, it marked the return of an old problem.
Remember the millennium bug and the Y2K scare? Moving into 2020 caused the bug's problems to return to the surface.
NewScientist covered the story:
Programmers wanting to avoid the Y2K bug had two broad options: entirely rewrite their code, or adopt a quick fix called "windowing," which would treat all dates from 00 to 20, as from the 2000s, rather than the 1900s. An estimated 80 per cent of computers fixed in 1999 used the quicker, cheaper option.
"Windowing, even during Y2K, was the worst of all possible solutions because it kicked the problem down the road," says Dylan Mulvin at the London School of Economics.
The theory was that these windowed systems would be outmoded by the time 2020 arrived, but many are still hanging on and in some cases the issue had been forgotten.