I saw something similar in Tokyo. It was at a telco office. A bell would ring (at 1pm IIRC) and an entire skyscraper's worth of office workers would get up and try to get to street level. Every day.

I was visiting a Western company that was renting a small space in the same building. Their routine was to never get caught up in the great migration (in either direction).

That was the routine at Safeco in Seattle well into the 90s. My wife temped there over summers during grad school. Although she says they played Muzak instead of bells. So, in fact, it was much worse.

D: What slave-drivers.