Why does your dog always seem to know what time it is?

It's 4.57pm. Dinner is at five.

Your dog is already standing in the kitchen, staring at you like you've broken some sort of legally binding agreement.

You look at the clock. Three minutes to go.

Your dog looks at you.

Unacceptable.

It's one of those things about living with dogs that never gets old. They can't read a clock, don't know what day it is and have absolutely no understanding of why you might be running late. Yet somehow, they know when dinner is due, when it's time for a walk and, quite often, when someone is about to come home.

So what's going on?

Your dog has a clock of their own

We all have an internal body clock. It's why you might wake up just before your alarm or start thinking about lunch at roughly the same time every day.

Dogs have one too.

It's called a circadian rhythm, which sounds terribly scientific for something that essentially helps the body work out when to sleep, wake up, eat and get moving.

Daylight plays a part, along with regular routines and the things happening around them.

If your dog has breakfast at seven every morning, followed by a walk and then a lengthy nap somewhere inconvenient, they'll soon become familiar with that pattern.

And once they've learnt it, good luck changing it.

Some dogs are quite relaxed about the whole thing. Others behave as though you've personally disrupted the natural order of the universe because breakfast arrived eleven minutes late.

You're giving away more clues than you realise

Here's something I find fascinating.

We think our dogs are watching the clock, but half the time they're probably watching us.

Think about what you do before taking your dog for a walk.

Maybe you close your laptop. Put your shoes on. Pick up your keys. Perhaps you always have a cup of tea first.

To you, these are ordinary things.

To your dog, they're clues.

Dogs are brilliant at learning what happens next. If putting on a particular pair of shoes usually means a walk, those shoes become very interesting indeed.

And if picking up your car keys means a trip out, you can guarantee someone will appear from nowhere.

Even if they were apparently unconscious on the sofa thirty seconds earlier.

This is particularly noticeable with a Velcro dog, the sort who follows you from room to room and considers a closed bathroom door a personal insult.

They're watching everything you do.

Not necessarily because they're keeping time, but because they've become experts in your daily habits.

Can dogs actually smell time?

Now, this is an interesting one.

We know dogs have an extraordinary sense of smell. They can detect changes in their environment that we wouldn't even notice.

There's a theory that dogs might use the way familiar scents change throughout the day to help recognise when certain things are likely to happen.

Imagine someone leaving for work every morning.

Their scent doesn't immediately vanish from the house. It gradually changes as time passes, air moves around and other smells come and go.

Could a dog learn that a particular change in scent usually happens shortly before that person returns?

Possibly.

It's a fascinating idea, but we should be careful here. There's no conclusive scientific evidence that dogs use fading human scent as a reliable clock.

What we do know is that dogs are very good at recognising patterns, including patterns involving smell.

Personally, I wouldn't be surprised if scent contributes to their sense of routine in ways we don't fully understand yet.

Although I suspect the sound of a food cupboard opening remains a considerably more reliable signal.

The dinner-time stare is something we've all experienced

You know the one.

It starts innocently enough. Your dog wanders into the kitchen and sits down.

You carry on with whatever you're doing.

A few minutes later, there's a gentle nudge against your leg.

Then the staring begins.

If that doesn't work, some dogs move on to pacing, sighing dramatically or standing directly between you and whatever you're trying to look at.

It's not necessarily that they're starving.

They've simply learnt that certain times, sounds and activities usually lead to food.

And if staring at you has resulted in dinner being served early in the past, they've also learnt that staring is worth trying again.

That's positive reinforcement in everyday life. A behaviour produces something the dog wants, so they're more likely to repeat it.

Quite clever, really.

We've probably all encouraged it without realising.

Why some dogs are more demanding than others

Not every dog is equally bothered about the schedule.

Some will happily sleep through breakfast if nobody disturbs them. Others appear to run the household with the precision of an airport departure board.

Breed traits can influence how closely dogs monitor activity around them.

A working-breed dog, for example, may be particularly attentive to movement, routines and the little signals that suggest something interesting is about to happen.

Dogs bred to work closely with people can be especially tuned in to what we're doing.

But personality, experience and what they've learnt at home matter just as much.

Take two dogs living in the same house.

One might be standing beside the food cupboard at precisely 5pm, while the other is upside down on the sofa, snoring.

Same routine. Completely different priorities.

And while we're talking about food, it's worth remembering that enthusiasm at mealtimes isn't the same as resource guarding. A dog protecting their food by stiffening, growling or threatening others is showing a different behaviour, one that needs a calm, careful approach rather than being dismissed as fussiness about dinner.

What happens when the clocks change?

Here's where things can get interesting.

On Sunday 25 October, the clocks go back an hour in the UK.

Your phone will adjust automatically.

Your dog hasn't received the memo.

If breakfast normally arrives at seven, their body may still be expecting it when the newly adjusted clock says six.

Some dogs won't care in the slightest.

Others will be standing beside your bed, wondering why you've suddenly become so unreliable.

If your dog is particularly attached to their routine, you can make the change a little easier by gradually moving meals and walks by ten or fifteen minutes over several days.

There's no need to make a huge fuss about it. Most healthy adult dogs can cope with some flexibility.

In fact, a little variation in daily routines can be useful, especially for dogs who become anxious when things don't happen at exactly the expected moment.

Of course, if your dog needs food at specific times because of a medical condition, stick to the schedule recommended by your vet.

Do dogs know when you're coming home?

This is probably one of the loveliest parts of the whole subject.

Plenty of people say their dog starts waiting at the window shortly before someone arrives home.

Sometimes there's a perfectly ordinary explanation.

Your dog might recognise the sound of a familiar car, hear footsteps approaching or notice something changing in the household routine.

Dogs are also very good at visual tracking. They notice movement outside, recognise familiar people and can learn which activity usually happens before someone walks through the door.

And yes, their internal rhythms and experience of daily patterns might help them anticipate regular arrival times.

There has even been research suggesting that dogs behave differently after longer periods apart from their owners, although that doesn't mean they're mentally counting the hours.

It's probably a combination of several things rather than one mysterious ability.

Then again, some dogs will greet you like you've returned from a six-month expedition when you've only been outside putting the bins away.

Which makes measuring their understanding of time rather difficult.

So, does your dog really know what time it is?

Not in the way we do.

They don't understand that it's Tuesday, that your meeting has overrun or that you've promised to be home by half past five.

But they do have an internal body clock. They learn patterns, notice tiny changes in our behaviour and build expectations around the things that happen regularly.

And they're often paying far more attention to us than we realise.

Put all that together and it's hardly surprising they seem to know exactly when something should happen.

Especially dinner.

Speaking of which, there's a dog standing in the kitchen looking at me.

It's 4.58pm.