We tested pretty heavily, setting BIOS clock and stopping ntp from resetting time, but despite proving to ourselves nothing would happen, one of my teams sysadmins said he hated fireworks, and for $200 agreed to stay in the machine room over the window. He texted me 5min into 2000 saying "nothing happened" and we all went to sleep.
Well, maybe it was a non-event because people actually fixed code in time. I helped QA test systems but never saw what changes were made. (investment bank) And the same outside my workplace. I don't know what needed changes were made.
I guess that non-disasters are not documented, nor made into movies :-)
It's so frustrating that some people think it was overblown. It was fixed in time, so the things that really could've happened, didn't.