Why was Y2K specifically a big deal if computers actually store their numbers in binary? Why would a significant decimal date have any impact on a binary number?

Question

I understand the number would have still overflowed *eventually* but why was it specifically new years 2000 that would have broken it when binary numbers don’t tend to align very well with decimal numbers?

EDIT: A lot of you are simply answering by explaining what the Y2K bug is. I am aware of what it is, I am wondering specifically why the number ’99 (`01100011` in binary) going to 100 (`01100100` in binary) would actually cause any problems since all the math would be done in binary, and decimal would only be used for the display.

EXIT: Thanks for all your replies, I got some good answers, and a lot of unrelated ones (especially that one guy with the illegible comment about politics). Shutting off notifications, peace ✌

In: 478

Answer 1

The numbers stored in binary weren’t the issue. If it was typed as an int or a float, no problem.

What we had, though, was text fields. A lot of databases stored stuff as plain text even when it really shouldn’t be. So they would store a year not as an integer but as two chars.

Or more to the point, perhaps they stored it as an integer but it would run into trouble when it was brought back out and placed into a text field where only two places were allocated, resulting in an overflow.

Plenty of stuff they shouldn’t have done, honestly, it took a lot of stupid mistakes to cause the bug but there they were.