The issue here is that Okrand’s language and the fiction of Klingon culture are quite frequently nudge-nudge-wink-wink very familiar to life on Earth without a lot of thought. Why does Klingon have a 24-hour day at all?

I'm on vacation, and it hasn't been convenient for me to respond to the very silly things you've been saying. I've got a moment now.

"Klingons have adopted the way most civilized planets in the Galaxy tell time. They have twenty-four hour days." (Conversational Klingon) Why would they do this? It's just a TV show; don't worry about it. A "galactic standard" time makes sense, and the humans driving the Federation to adopt "Earth standard" time also makes sense in a "we barge in and tell you to do things our way" kind of way. And I have no doubt that all the various planets have their own local versions of time-telling that we're not told about.

And it doesn't matter. Okrand could have told us that Klingons have thirteen-hour and forty-five minute days, and klorns and bleems instead of hours and minutes. It wouldn't have changed anything. People would be complaining that knowing the Klingon words for klorns and bleems were useless and would be pining for hours and minutes.

So yeah, the fictional Klingon culture is frequently nudge-nudge-wink-wink very familiar. If you've only noticed this now, you haven't been paying attention. If you've only recently decided that this is unacceptable to you, you've spent a lot of time learning a language you're not going to enjoy.

 Meanwhile, we quite commonly assume that a Klingon hour is exactly as long as an Earth hour.

It's completely irrelevant whether it is or isn't. If it is, then they're just using the same "galactic standard" time. If it isn't, then they've adapted it for Kronos. When someone says rep, they just mean whatever equivalent "hour" is in the local time system.

I’m not sure that it has been explicitly stated that a Klingon second, minute, and hour are of identical length to the human time units of those durations, yet we quite comfortably behave as if that is true. And now, you want to get all huffy about the absurdity of assuming that the unexplained “traditional” Klingon alternative to military time could possibly be a 12 hour clock.

No one but you is getting huffy, but people are resisting your absurd objections. Others were perfectly willing to admit that there is no explicit proof that the Qoylu'pu' style of time-telling uses twenty-four hours, but when asked if you had any evidence for it using only twelve hours, your response is to rant about the foolishness of the fictional setting. Why not just say "I don't know" and move on?

Riiiiight.

And time zones? Well, Star Trek never thinks about time zones, nor does it explain how measuring time works without them.

Measuring time without time zones is easy. Everyone sets their clocks to exactly the same time. The idea that you go to work at 9 in the morning and leave work at 5 in the evening is a completely arbitrary convention that is not necessary to run a planetary society. So people on the other side of the planet's prime meridian will experience midnight at 1200 hours and noon at 0 hours. So what?

The Science Asylum just did a video on this: https://youtu.be/DHIQxVhruak

In fact, I'll bet you can't even point to any evidence that this isn't exactly what any or all planets in the setting do.

I'm not saying it is what they do, just that it doesn't really matter all that much.

I feel quite comfortable assuming that the traditional Klingon clock is a 12 hour clock until we are told otherwise. Yes, we can imagine other time systems, but they aren’t American, and in this Universe, pretty much everything is comfortably familiar to Americans, unless Okrand wants to make a joke out of an unexpected difference.

He can do that whenever he wants. And we can’t.

-- 
SuStel
http://trimboli.name