Sorry, previous commenter said something along the lines of "Trains always on time to the second" which prompted my response.

I don't know the exact numbers they use for their statistics (I think it used to be 1 minute).

If a train is delayed by 10 minutes you can ask for a ticket to take to work to show your boss that being late was not your fault.

Don't get me wrong, the punctuality is much better than most European countries I have lived in and quite a lot of the time the are perfectly on time, but the west has raised the Japanese public transport system to near mythical status.

Depends on what type of train I guess. Probably no bullet train (shinkansen) has even been more than 59 seconds late (under normal circumstances that is). Naturally any type of bad weather like blizzards, typhoons or earthquakes will cause delays but most likely due to a complete cancellation of service.

Local trains are more prone to delays, for example the Yamanote line in Tokyo being the most notorious due to ahem, being the preferred line used by Tokyoites to say bye-bye to this world.

For local city train lines a delay of more than 5 minutes will result in the driver profusely apologizing on and on, and the line to start issuing "certificates" that people can get to show their employers blaming the lateness on the train line.

Sometimes they arrive 1 or 2 minutes late due to stuff like urgent track inspection/maintenance. This is generally not considered a big deal, although the conductor will still announce it and briefly apologize for it.

Leaving 6 minutes (let alone 11) later than the schedule is definitely considered late. If you're changing lines, which in practice most people have to do when commuting in Tokyo, a 5 minute delay can result in an even bigger total delay (e.g. if the next train you take is an express one, and it comes every 15min).

Delays longer than that are usually due to bodily accidents which is an euphemism for "someone just jumped in the tracks", and typhoons and other natural accidents. The former is more common.

What I found more amazing when I fist came is that buses also come on time! Although of course short delays are more common than with trains, they're pretty much on schedule. The flip side is that they run very slowly and stop every other block. When I used to commute by bike I often kept up with buses for long stretches.

For frequent trains like like loop lines and subways in major cities, you can generally expect them to arrive when scheduled. These arrive every few minutes, so anything longer than a minute is perceived as a delay. These will be reported and apologized for.

For trains like JR that run longer distances and less frequently, delays of 15-20 minutes due to accidents or weather can happen. This seems to happen once every few months or so.

When there isn't a typhoon on, they pretty much arrive on time to the second. Anything later than a few minutes results in the platform staff handing out notes to that effect so that employees can prove to their companies that the train was actually late.

In India, if a train arrives, it is considered 'on time'.