Why don't the whole planet just use UTC+00:00 / Universal Time without time zones?

Fantastic article. Never seen it. Thanks for sharing!

Time is confusing. We should all just use Unix Timestamp. Meet me at 1748918019!

That's literally how computerized calendars work, so unironically this
Are we could use .beat time

Why isn't this a popular thing? Because the majority of people on this planet does not care about time zones and either doesn't have to deal with them at all or doesn't see a problem when they do. It's tradition, it's convention, it's well-established, and it just works for most people. We should abolish DST but otherwise this ship has sailed.

We should use the aftermath of a civilization killing meteor hit or thermonuclear war to decimalize time keeping - it would need a catastrophic, cataclysmic event like that. A day is now 100 jiffies long. Each jiffy has 100 centijiffies. Now, if we could alter the time it takes the Earth to orbit the sun to something more even that'd be great.

Why isn't there 72 Jiffies in a day and 90 Iffs in a Jiffie? Centi seems very regulated for post apocalyptic time.
- Because we don't want an American system where 16 blorbs equal 1 waboom. We want as much centi and milli as possible! Resistance is futile.

Because it rather tells time... sun-wise, if that explanation makes sense. If you want something worldwide for some large event, you simply mention the timezone.

What we should eliminate is summer and winter time.

Because my noon is the best noon, and your silly noon is unreasonable. It happens at 4am, you silly goose.

Once upon a time, when airplanes where not a thing and real time communication implied a distance that you can scream to... When only snail mail or telegraph where available and people traveled by boat and train...

You would never experience jet lag nor have the problem of knowing if people far away was ssleeping or not.

In this scenario, when time was standardized and organized, it only made sense that everybody would wake up and go to bed at the same time no matter where their lived (more or less, of course ,you get the meaning). Thats when time zones where defined, so that people traveling by boat or train would keep waking up day after day at the same time of the day.

Without time zones, life would be quite difficult to organize and understand. Ask to the Chinese, that live in the Beijing timezone in a country spanning three time zones. They keep using mixed local and Beijing times... And catching trains and airplanes is a mess for this reason...

No, timezones are really needed. Not having them would be weird and messy.

Day/night cycle, the local time usually matches with the local day/night cycle which is far more relevant than international communication of time
Tradition, some countries have weird time zones, but it's a lot of effort for little gain to change that

Even though there is a day night cycle, the time for sunrise varies by location anyways (and they also change during different time of the year)

We already arbitrarily decide a number to be "morning" anyways, what's the harm in having each place have their own time range for "morning"?

It's mostly with how society decides that the standard office hours is 9-5, if we are not restricted by such constraints, then it really matters less.
- at some point we would have to shift the date and it’s much more convenient to do that at night

Imagine if every time you read a news report, or work of fiction, or gardening manual, or anything where the time of day is relevant, you’d need to know what longitude the text originated at and then mentally convert it to your familiar local time before you know whether the events described are in the morning, afternoon, or night.

Because despite all of our modern technology we are still very much bound to the cycle of night and day. Right now if someone says 'Hey let's meet online at noon' you have to ask what time zone they're in and do a little dead-simple math to figure out what time that is for you. Oh you're EST and I'm MST, noon for them is 10am for you. Not particularly hard, but a little irritating. On a system like you suggest you wouldn't have to do a little addition/subtraction to figure out what time it would be for you, you instead have to do some more complex math based on when the sun comes up for you and figure out if you'll even be awake at that time. You're hosting a meeting on west-coast US time and one of the people in that meeting and they're on the east coast of Australia. Noon your time and noon their time is the same, but for them noon happens at what might otherwise be in the middle of the night, so they'll definitely be asleep.

Really this is the simplest version because we all still mostly wake and sleep with the sun.

Why calculate?

While 1200 might be noon for one, another might just get used to 0800 to be noon. Who says 0000 must be midnight and 1200 noon?
- You just recreated time zones
- If I am set to arrive in Bejing at 18:00 UTC that gives me 0 useful information without calculation.
  
  Knowing that I will arrive at 2am local time is much more useful, it tells me it'll be dark and most shops won't be open.
- While 1200 might be noon for one, another might just get used to 0800 to be noon.
  
  Aside from the fact that that's just timezones with extra steps?
  
  Who says 0000 must be midnight and 1200 noon?
  
  Thousands of generations of human history/prehistory? We are used to being awake during the day because we use vision so much for everything we do, so we sleep when it's dark.
- Why even decide what is noon? Sam works from 1600 to 0000, so when we want to have a meeting with Sam we just take in consideration of that time range, screw letting the sun dictate how we live our lives. (This also makes it friendlier to nocturnal people)

Why would it be? What would planetary time solve that local time makes an obstacle?

Why arent we using only X because Y is inefficient.

No idea, I've been using UTC both while travelling and at home (which is not located in the UTC time zone) and it is not significantly more difficult than using 24-hour time in a customarily 12-hour country.

Considering general relativity exists, it's fitting that each place has its timezone.

I'm a fan of Swatch Internet Time myself!

They do on their servers. For human activities, having times relative to the diurnal cycle makes more sense than having to do the mental arithmetic.

I would venture to guess it had to do with noon. It would have always been easy to say sunrise, sunset or noon even before a clock or sundial were invented. Remember there were no aircraft flying through the timeshifts. The effects of time on long distance travel were negligable if noticeable at all. Communications also traveled slowly. Once technology introduced clocks, you could see how your noon no longer aligned with the sun a couple hundred miles east or west. Your clock would not match the place you are visiting as noon had hands both pointing straight up as where the sun would also be located at that time. Your question only becomes relevant when we get light speed communication like radio and telegraph.

"Good afternoon German friend how is the weather today?" "WHY ARE YOU RINGING ME IN THE MIDDLE OF THE NIGHT, AMERICAN FRIEND!?" Not a real conversation, but you can imagine.

The answer: people hate change.

After reading the lack of consensus in the comments, I'll just be over here using decimal time, confusing everyone around me. ;)