While I appreciated your source 1.) I doubt 99% of Europeans work during 3am - 9am 2.) At least there can be other reasons: 2a.) EU times and African times are basically the same and Africa has a huge population. 2b.) India is closer timewise to EU/African time zones 2c.) What are about posts afterworks?

" RL conversation topics in the Bay Area tech scene are entirely different from those on HN shows a massive divergence in userbase. " Any proof?