When do the most earthquakes happen?

I am planning on traveling to Tokyo this summer and was wondering when do earthquakes usally occur?

They usually occur when you least expect them.

In my experience they hit when you are in an upper floor in a high rise building, just so that you can enjoy them that much more.

Not sure I understand the question as there is no set time for earthquakes. It's not like there is an 'earthquake season' that happens. They have them all the time, you can follow the info on the Japan Meteorological page http://www.jma.go.jp/en/quake/quake_singendo_index.html and you will see they have tremors several times a day in varying places. Will you feel them? Unlikely for the most part, although I have felt two there before now around the 5 mark and they were mere seconds. Are you likely to experience a major quake? You'd have to be very unlucky. Just make sure you know what to do and don't let it stop you going!

Earthquakes happen all the time - it's just that the big ones (the ones you notice) are infrequent and random. You never know how big or long they are going to be which is why people find them scary.

So far I've only had one really decent one in Japan, and I was 200km away from the centre at the time (it demolished 40 buildings in Nagano, I was in Nagoya.

However, I live in an earthquake prone country and almost on top of a fault-line, so I am not too upset by modest sized ones (into the mid 5's) and I have a sensor somewhere in the house that contributes to an international research project on them.

As a trained geologist - I think it's fair to say that there is no specific earthquake season like there is for typhoons (August - October).

Also predicting earthquakes is a very imperfect science - I kind of see it like water divining (finding water with a stick)

However, if there has been a major earthquake (like the one a few years ago) then they can be followed by many aftershocks which are of differing strengths (even the same size or potentially bigger than the first one).

Just remember that an earthquake tends to release stress which means lots of small earthquakes tend to stop or reduce the chance of a large earthquake happening.

Apologies if I sound like a teacher here - it may be because I am one!

When?
How strange just "God" only knows.

Read all.
http://www.japan-guide.com/forum/quereadisplay.html?0+126039

This is records of past from latest.
http://www.tenki.jp/bousai/earthquake/entries
Last 100 days shaked over 470 times as over "level 1".
http://www.jma.go.jp/en/quake/

When the tectonic plates are moving, colliding, and pulling apart. That is when earthquakes occur.

Sorry Quayke - your knowledge seems a little shaky to me.....

Being from Miami, you should know the answer - at the same time as hurricanes occur. 3:14 PM. - DUH!

Earthquakes are really nothing like hurricanes - hurricanes and other large weather systems are large forming masses on energetic air and moisture with long lead times and comparatively predictable paths. Time scale = hours to days of warning.

Earthquakes arrive without warning, of unknown strength. You don't know if it is a fore-shock or the main event, if it is going to get stronger, longer or even (often) if it is just the p-waves or s-waves. If you know what to listen for - you can even hear them coming therefore time scale = 0 to a few seconds of warning.

Really? Wow, I had no idea! Thank you so much for the education.

If you were really serious, you obviously have a poor sense of humor - or is it humour? :)
Or if you are Japanese I can understand that you do not understand western humor.

No problem Dick - happy to provide you an education :P You might also like to know humour or wit is difficult to convey on a forum.

I live in New Zealand and have grown up with earthquakes so they are nothing new, but most people have never experienced one, nor do they know much about them. And I do get serious questions from people about earthquakes in Japan and how to avoid them. Along with aversion to typhoons , worryies about radiation, concerns about crime and all sorts of other mostly pointless questions, but for the person asking them, they might simply not know and they are important enough to them to ask in the first place.

Thus the OP asked about earthquakes, and there are a bunch of answers - some more useful than others.