Back in 1999 in SF, at the peak of dotcom boom, a few startups located down South from the Market street would shutter down their entrances after around dinner time. All people still inside, working over night. I had two of my friends (actually colleagues - we were from a consulting firm) working at those places. It became a norm around that place and youngsters loved that kind of all-nighters.
The new year eve of millennium Dec 31, 1999 - we went to Fishermans's wharf, roamed around and then went back to work at 1 am. No Y2K issues.
replies(2):