We all have a friend or colleague, who is never on time. They don’t mean to annoy us or think they’re entitled to being late – it’s just in their nature. While successful time management can be easy for some, others just never get round to learning the art of schedule prioritisation.If you’re not one of those people, you’re bound to be perpetually annoyed with those who always seem to be late. Unpunctuality is incredibly unpopular – especially in work life. Different cultures have different understandings of time, but especially in our Western world today being late for something is seen as rude and unprofessional. We should stop scolding people who are late. They’re most definitely not lazy, it could even mean they have a whole lot on their plate. Multitasking makes you lose all sense of time. Sure, some studies question the efficiency of multitasking, but especially successful people tend to do more than one thing at the same time. Think of actor-turned-entrepeneur Ashton Kutcher for example, who is a producer, runs a viral media company and famously invests in numerous start-ups and tech companies such as Skype, Spotify, Uber, and Foursquare – all while being one of the most successful actors of our time.If you notice you’re constantly running way behind schedule, it could be because you’re an optimist. Yeah, you read that right. If you’re an optimist, you tend to think you have more time on your hands than you actually do. Makes sense, doesn’t it? And this kind of positive thinking is the same personality trait which makes you more successful in life: a study among salesmen shows, that optimists tend to complete 88 per cent more sales than their colleagues.But there’s more. Optimism – again: the personality trait responsible for your tardiness – makes you live longer. If you go through life with a positive attitude, your heart will thank you for not being put under a whole lot of stress.In the 50s researchers started dividing people into two different personality groups: type A and type B. While the former makes you competitive and impatient, the latter makes you relaxed and creative. So being late a lot would suggest you’re in the type B category.A study shows that the two different types have a complete different perception of time: after one minute the research participants had to guess how much time had passed. People from subject group type A guessed at an average of 58 seconds while those from group type B thought in average that 77 seconds had passed.To sum up: it’s not your fault you’re late. You just perceive the world differently than your moaning friends.For type B people, being an optimist is a positive thing. They tend to see the big picture rather than distracting themselves with details. If they miss an appointment, maybe that’s because they are having an incredibly creative idea. Next time someone scolds you for being late, just refer them to this article. It’s science.