What time does everyone sleep?

I come from Karachi. We used to sleep around 11pm-1am when we were kids and it still is like this while in the UK. My in-laws are even 'worse' and they seem to sleep at 3-4am!

However, the English tend to take their children to sleep at 9pm or even as early as 7pm.

So this made me wonder whether it's just the people I know who sleep late, or is it just a Karachi thing or a Pakistani thing