Old joke I heard on the radio years ago: a Lancastrian wore a meat pie strapped to his wrist, and when asked why he did that, he replied, "Well, when I need to check the time, I look at my wrist and I see it's summat t'eight!"
You had to be there.
But anyway, in terms of comprehension of time, I generally didn't have much problem with it. Learning the analogue clock with the first hand, the second hand and the other second hand, all was something that school actively tried to teach us. Ironically, I can't actually remember when I started to figure out the analogue clock with confidence, but by the time I was 3 I was capable of telling when a weekend was (yay! two days off nursery and wrestling with Big Daddy on the telly!) and around the same time I had understood the concept of birthdays (YAY! One day of presents!).
However, the digital timepiece including the 24 hour clock was something I picked up by myself at an early age, and coincided when my dad bought our first video recorder (a VHS Ferguson VideoStar, as it happens) which had a digital display and 24 hour clock by default. I remember that I would take the digital display and correlate that with what the analogue clock in our house said, and it very quickly clicked that this clock measured total hours in a day as opposed to the traditional am/pm system.
I do have very fond memories of mathematics as a young child, although I understand that I was a very slow learner who picked things up quickly later in childhood. When I was 4, my mother would write out the numbers 1 to 100 in a 10x10 grid, and I remember taking a lot of pleasure in knowing that there were numbers out there greater than 10.

The concept of thousands and millions and things came later than they should have come, as did percentages and world currencies, although I did understand decimals a few months before most others did at school. Maths was my favourite school subject back then, and probably the only one I truly grasped with both hands at a young age, although my teacher did say that I was also good at creative writing during those underachieving years.
Those days are long gone now.
Just for context for those who are uncertain about when it's "normal" to tell time, most kids have a pretty messed up comprehension of time until about the age of 4-5.
Kids:
Tomorrow, or even
later is
ages away.
Adolescents:
Next summer is "when I'm ooold".
Adults: "I'll wither away before it's week-end again" AND "what?... is it already Monday again?"
Old people: "What?
me 'old'? -but I just finished college..."
I'm basically saying the same as science:
time is relative, only it depends on the amount you've already had
as well as your speed and the strength of the gravimetric field you are in.
^I guess
everyone has a pretty messed up comprehension of time.

But yeah, that's taking it to a whole other realm of complexity! That's more perception of time than comprehension of time, really. Everyone's perception of time is different, and different at different times, but our comprehension of the concept of time develops just like our motor or language skills, and follows a developmental timeline that is generally consistent.
Well, now that you two have brought up the subject

I have found that when I'm feeling tired out, sometimes I note that a familiar piece of music on the radio or my computer does seem like it's playing at a slightly slower tempo than what I'm used to in my memory - it feels off by maybe one or two beats per minute, at least temporarily, even though objectively the recording is playing at an uninterrupted, unimpeded tempo.
Similarly, the dream state is another whole different landscape entirely when it comes to comparing the perception of the passage of time. When I start to nod off to sleep while something is playing in the background, it feels as if the live radio or TV broadcast momentarily skips when I start to nod off while still listening to the broadcast, then suddenly I wake up to catch up with the rest, and it feels like the dream-like state has added seconds to my mind's internal chronology of events.
My mind is an awesome place, but I wouldn't want to live there...

Nah, I kid, it's not too bad.
