What time is the Internet the busiest?

This question has two answers, the short and the long.

The short answer is:

The internet does not really have a 'busiest' period. There is no 'cyber rush hour'.

The long answer is:

The internet is a global thing. It is available in most if not all countries world wide, which means that there are constantly people coming online, using the internet and then going offline, 24

Due to this, there is no time at which the internet is busiest. While you may be logging off to go to bed, someone on the other side of the world might be starting their morning on their computer to check emails and such.

That said, certain areas of the world have much higher population density than others, and also are better connected - meaning more people have internet access. Theoretically, then, there is no peak period, however if you could some how generate a graph of all internet activity then there may be an overall peak when the best connected, and most densely populated areas 'come online' - this would probably be early evening (local time), when people finish work and come home, kids get out of school, and so on.

Japan, for example, has a very high population density and the population is very well connected, however most of the Japanese users will visit Japanese websites which, presumably, are hosted inside Japan. Then again, for English speaking users, demand will be spread across the 24 hour period much further (as English is more widely spoken than Japanese), and would probably peak at some point during the day in the USA.

In summary, then, there is technically no time at which the 'whole internet' is busiest due to the global user base, however local demand will fluctuate, peaking every 24 hours at the time at which most of the local internet users come online. In Europe, my experience is that this tends to be early to mid evening: from about 6.00pm until 9.00pm, local time.