... and it's exhuasting to adjust to when business trips take me from SF to NYC. I usually add two hours to whatever normal evening meetup time I'd suggest in SF when I make plans with my NYC friends.

Definitely this, it's ridiculous how early stuff closes around here and how early people go out. Moving from Mexico it was a big shock.

This doesn't square with my perception of SV programmers always mentioning staying late to hack on their startup. Do they actually mean that they got there at 6AM, so staying until 5PM is "late?"

Engineers might stay up until 2am, but they stay up until 2am at home because nobody else is bugging them. If they eat, it's gonna be cheap stuff or frozen trader joes food from the freezer, more time efficient.

I don't think that it's all hackers. Without mentioning the neighborhood (because this borders on stereotype, and these things usually devolve into an x vs. x neighborhood discussion), I live in a neighborhood where people mostly hold non-technical titles like "marketing manager" and "product manager".

And they've all worked out, shopped for groceries, had breakfast, etc. before 9am.

The only way I could handle my old SF boss expecting people in the office by 7:30 was by being based in Dublin and only making the occasional trip to SF.

Even then, the jetlag only made it work for a week or two.