If you are wondering, yes, many of the stereotypes about punctuality are true (says a Chilean that's currently arriving late to his first class of the semester, along with many of the university students). But what's behind them? A field of research, sometimes called Sociology of Time attempts some explanations.
Observing the overall pace of timed activities of different societies, they have developed the categories of time-oriented and time-relaxed societies. On a known experiment, Robert Levine et al. measured the speed of people walking on city centres, the time a postal clerk took to sell them a stamp and how precisely timed were several public clocks.
What they found is that most Western European societies, along with the US and Japan are consistently time oriented societies, where people walk fast, work efficiently and care about keeping clocks working as intended; in counterpart, most Mediterranean, Latin American and Middle Eastern countries (those categories overlap) are time-relaxed, meaning that we focus less on punctuality, plan ahead for customary lateness and don't care about occupying other people's time.
A clarifying example is shown by Levine and recognise by many other scholars that share his experience: while giving classes on time-oriented countries they could count on their students arriving in time, but were also frowned upon if they extended the class after the scheduled time ends, with students abandoning the hall. On time-relaxed cultures, arriving late is generally seen as admissible, even for the one giving the class, but leaving a classroom before ending is widely regarded as impolite, while extending it is took as a 'gift' from the scholar to their students.
Further analysis has observed that time-oriented cultures tend to be richer, more individualistic, more stressed and to develop on colder climates, but there's no clarity on how this factors are related to time perception.
Also, there are cultures that aren't fully time-oriented nor time-relaxed, as Korea, where lateness is considered very impolite, but end times are much more flexible. Similar phenomena occurs on developing countries, where most people retain a time-relaxed culture but economic and political elites have synchronised themselves with foreign time-oriented cultures, as in northern Mexico, where both hora inglesa and hora mexicana are selectively used depending on the situation.