Is it too much to ask that people turn up to meet you when they say they will?

The texted ‘Sorry, be there in 5’ is a curse of the Internet age

The app is due to be launched in San Francisco initially, with other 300 people currently on the waiting list (Rex)

"Punctuality is the politeness of kings". We've come a long way from Louis XVIII's famous assertion to the idea that being late is fashionable.

Punctuality is now a quaint, outdated custom, as inimical to modern life as curtsying or dressing for dinner, a courtesy that the age of mobile communication has comprehensively done away with. Who needs to be on time now when you can send a text to say you'll be late? Such are the mores of social life today.

Because I am old enough to remember an age when you simply had to be on time, I find the modern penchant for lateness irritating in the extreme.

"Be there in 5," comes the text when you are sitting alone at a restaurant table or waiting in the street at the appointed hour.

You just know that means at least 15 minutes, as accurate an estimate of time as the mini-cab driver who insists he'll be with you any minute. This casual approach to punctuality is, as the old king would say, speaks of impoliteness and disregard.

And what about those who blame the London traffic? I'm really sorry, they'll say, but the traffic was an absolute nightmare. Really? Bad traffic in central London? In the middle of the day? Who would ever have thought it?

No, what they should really say is this: I left too late to get you on time, and I knew this wouldn't matter because I have my mobile phone and I can ping you a text saying that I'm stuck in a jam at Trafalgar Square.

And when they eventually arrive, in a flustered, distracted state, they expect you to feel sorry for them because they've had a difficult journey.

At moments like these, I turn to Debrett's, the arbiter of such things, to see what they say on the subject.

"Failing to be punctual is the height of bad manners," they say. "Conversely, being punctual always scores bonus points.

By being late for a meeting, you are effectively forcing your colleagues or clients [or indeed friends] to waste their time; hanging around waiting for someone to show up is deeply frustrating. If you see that you're going to be late, pre-empt the fall-out and call ahead."

Notice that Debrett's advise calling ahead, not texting. The alacrity with which people deliver bad news by text is particularly concerning.

We may even be raising a generation of people who are unable to deal with conflict because these sort of exchanges are rarely conducted face-to-face, or as part of a real-life conversation, but are lazily communicated with a few key strokes dispatched into the ether.

Why we still need table manners in society

And then there is the real shocker: those who flake out of an arrangement at the last minute, and then deliver the news by text.

What happened in the days before mobile phones? We made a plan and we bloody well stuck to it.

Perhaps there were fewer phantom illnesses in those days, or babysitters were less inclined to go missing, but I think it's because the world was a more serious place and people were more responsible about not letting down friends and colleagues.

It wasn't just kings who were once polite.