Aspects of that industry do run 24/7 - it doesn't necessarily follow that shops, restaurants stay open just because some IT guys are working or some people are covering for guys in Asia, the US etc...
I meant if the whole sector stayed open, rather than just the few people that do now. If there was as many people working in the city over night as there was during the day then all the services that serve them could be fully open 24x7 too.
Its cheaper to just follow the sun and have 3 offices in 3 timezones though.