Y2K required hundreds of billions of dollars worth of effort to keep it from being a disaster, and it still actually resulted in some significant issues:
"In Sheffield, United Kingdom, a Y2K bug caused miscalculation of the mothers' age and sent incorrect risk assessments for Down syndrome to 154 pregnant women. As a direct result two abortions were carried out, and four babies with Down syndrome were also born to mothers who had been told they were in the low-risk group."
"In Sheffield, United Kingdom, a Y2K bug caused miscalculation of the mothers' age and sent incorrect risk assessments for Down syndrome to 154 pregnant women. As a direct result two abortions were carried out, and four babies with Down syndrome were also born to mothers who had been told they were in the low-risk group."
https://en.m.wikipedia.org/wiki/Year_2000_problem