We've all been there. Your car has broken down. The train inexplicably failed to turn up on time. Your dog ate your alarm clock. And so on, and so forth.
While running late might not be ideal, it does happen, and sometimes it's really, truly, legitimately not your fault. Sometimes.
More often than not, however, tardiness isn't due to a random fault in the public transport system, it's a fault in the way we perceive the value of time (namely, other people's).
"Essentially, running late is very poor manners," etiquette expert and founder of The Good Manners Company, Anna Musson, told The Huffington Post Australia.
"There are a multitude of reasons as to why, but the overriding reason is it suggests deep down you think your time is more valuable than others'."
Someone is always on the other side of your thoughtlessness.
"If you think back to when etiquette was at its peak, so during the Victorian times, there were often six course dinners all perfectly timed according to wine and service," Musson continued.
"If one person is late, it could throw out the whole evening. What people forget is someone is always on the other side of your thoughtlessness."
While six-course meals aren't exactly commonplace these days, Musson says repeat tardiness is still of significant consequence and shouldn't be taken lightly.
"Where we are seeing this in epidemic proportions is in the workplace," Musson said. "It's like an unspoken rule with meetings to give people five minutes either way. This tends to mean every meeting runs five minutes later.
"There are also complaints younger people have an attitude of 'the meeting starts when I get there', which annoys people and also affects productivity.
"The bottom line is, being late costs people money."
Musson says while occasionally running late is out of everyone's control, you don't want to be in a position where you are known for your tardiness.
"If you are habitually late, it suggests you are unreliable," she said. "In fact, in my experience, elite business people or elite performers will tend to be 15 minutes early. This just goes to show their commitment to excellence and that next level of professionalism.
"You don't want to be in a position where you are keeping that person waiting."
However, if worst comes to worst and you are running behind, Musson says the best thing you can do is to pick up the phone as soon as you realise you're going to be late.
There is no such thing as arriving fashionably late.
"A phone call is much better form than a text for business but if it's a friend, a text is probably fine," Musson said. "Never send an email saying you are running late.
"Also, sending one at five past, when you are already late, is really bad form."
Once you have arrived at your scheduled meeting, Musson said while it's appropriate to apologise, it's not appropriate to go on and on about it.
"If the circumstance is out of your control and you have arrived and you are late, apologise for running late, and then let it go," Musson said.
"It's a negative thing, so to keep bringing it up is a real downer. An apology is appropriate, then quickly forge ahead, get their mind off it and get onto something else."
As for the concept of arriving 'fashionably late', Musson is not a fan.
"There is no such thing as arriving fashionably late," she told HuffPost Australia.
"The correct time to arrive for a business meeting would be 10 minutes earlier than the agreed time. Earlier than 10 minutes is not appropriate -- in fact it's bad manners -- as it makes the person anxious.
"For a dinner party, the correct time to arrive is 10 minutes after the specified time. This is the only occasion when being 'late' is acceptable, and it's not because your time is more important than the host's, it's because you are allowing them a buffer to get everything ready."
Today, for many people, it's common to have a more fluid view of time rather than a linear and finite view. I don't agree with that.
"I once had a friend who used to say, 'the party starts when I get there,' and I just used to think, 'wow, that's really arrogant'," Musson continued.
"Don't forget you are a guest of the host, and should be gracious and turn up at an acceptable time. You are fortunate to be invited. They aren't lucky to have you. It's all about having that respect."
In terms of the somewhat lax attitude many people have today toward time, Musson acknowledges advanced technology could play a part, but urges this should not be the case.
"The thing is, though it is a tool to help ease the pain of being late, we rely on it too much," Musson said. "There is this presumed flexibility whereas we don't know what the other person's day might look like.
"We should use technology as assistance, not as a crutch."
For those who find it difficult to be on time, Musson says the best thing to do is pretend your meeting starts half an hour earlier than it actually does.
"I used to be a serial runner-laterer, and I have learnt to tell myself to be half an hour early. That way I'm usually 15 minutes early," Musson said. "It takes a certain amount of self awareness to say 'I'm not going to do what I always do' but in this case it's very much worth it.
"Today, for many people, it's common to have a more fluid view of time rather than a linear and finite view. I don't agree with that.
"It's not endearing, it's not cute, it's a flaw."